feat(audio-sequences): beat phase sync and aligned playback

Add bar-phase tracking, audio reset/anchor APIs, BPM holdover, beat-phase
sequence switching, sync-phase endpoint, and sample sequence data.

Co-authored-by: Cursor <cursoragent@cursor.com>

db/sequence.json

@@ -1 +1 @@
-{}
+{"1": {"name": "Pulse (manual)", "profile_id": "1", "group_ids": ["5"], "lanes": [[{"preset_id": "6", "beats": 1}]], "lanes_group_ids": [["5"]], "advance_mode": "beats", "steps": [{"preset_id": "6", "beats": 1}], "step_duration_ms": 3000, "simulated_bpm": 120, "sequence_transition": 500, "loop": true}, "2": {"name": "Off (1 beat)", "profile_id": "1", "group_ids": ["5"], "lanes": [[{"preset_id": "2", "beats": 1}]], "lanes_group_ids": [["5"]], "advance_mode": "beats", "steps": [{"preset_id": "2", "beats": 1}], "step_duration_ms": 3000, "simulated_bpm": 120, "sequence_transition": 500, "loop": false}, "3": {"name": "On (1 beat)", "profile_id": "1", "group_ids": ["5"], "lanes": [[{"preset_id": "1", "beats": 1}]], "lanes_group_ids": [["5"]], "advance_mode": "beats", "steps": [{"preset_id": "1", "beats": 1}], "step_duration_ms": 3000, "simulated_bpm": 120, "sequence_transition": 500, "loop": false}, "4": {"name": "Rainbow \u2192 transition \u2192 off", "profile_id": "1", "group_ids": ["5"], "lanes": [[{"preset_id": "3", "beats": 4}, {"preset_id": "4", "beats": 4}, {"preset_id": "2", "beats": 2}]], "lanes_group_ids": [["5"]], "advance_mode": "beats", "steps": [{"preset_id": "3", "beats": 4}, {"preset_id": "4", "beats": 4}, {"preset_id": "2", "beats": 2}], "step_duration_ms": 3000, "simulated_bpm": 100, "sequence_transition": 500, "loop": true}, "5": {"name": "Manual pulse + chase", "profile_id": "1", "group_ids": ["5"], "lanes": [[{"preset_id": "6", "beats": 2}, {"preset_id": "5", "beats": 2}]], "lanes_group_ids": [["5"]], "advance_mode": "beats", "steps": [{"preset_id": "6", "beats": 2}, {"preset_id": "5", "beats": 2}], "step_duration_ms": 3000, "simulated_bpm": 120, "sequence_transition": 500, "loop": false}, "6": {"name": "RGB solid cycle", "profile_id": "1", "group_ids": ["5"], "lanes": [[{"preset_id": "11", "beats": 2}, {"preset_id": "12", "beats": 2}, {"preset_id": "9", "beats": 2}, {"preset_id": "10", "beats": 2}]], "lanes_group_ids": [["5"]], "advance_mode": "beats", "steps": [{"preset_id": "11", "beats": 2}, {"preset_id": "12", "beats": 2}, {"preset_id": "9", "beats": 2}, {"preset_id": "10", "beats": 2}], "step_duration_ms": 3000, "simulated_bpm": 90, "sequence_transition": 500, "loop": true}, "7": {"name": "Winter trio", "profile_id": "1", "group_ids": ["5"], "lanes": [[{"preset_id": "64", "beats": 8}, {"preset_id": "65", "beats": 8}, {"preset_id": "66", "beats": 8}]], "lanes_group_ids": [["5"]], "advance_mode": "beats", "steps": [{"preset_id": "64", "beats": 8}, {"preset_id": "65", "beats": 8}, {"preset_id": "66", "beats": 8}], "step_duration_ms": 3000, "simulated_bpm": 80, "sequence_transition": 500, "loop": true}, "8": {"name": "Fast rainbow", "profile_id": "1", "group_ids": ["5"], "lanes": [[{"preset_id": "1", "beats": 1}, {"preset_id": "3", "beats": 4}]], "lanes_group_ids": [["5"]], "advance_mode": "beats", "steps": [{"preset_id": "1", "beats": 1}, {"preset_id": "3", "beats": 4}], "step_duration_ms": 3000, "simulated_bpm": 180, "sequence_transition": 500, "loop": true}, "9": {"name": "Off then on", "profile_id": "1", "group_ids": ["5"], "lanes": [[{"preset_id": "2", "beats": 2}, {"preset_id": "1", "beats": 4}]], "lanes_group_ids": [["5"]], "advance_mode": "beats", "steps": [{"preset_id": "2", "beats": 2}, {"preset_id": "1", "beats": 4}], "step_duration_ms": 3000, "simulated_bpm": 120, "sequence_transition": 500, "loop": false}, "10": {"name": "Twinkle + flame", "profile_id": "1", "group_ids": ["5"], "lanes": [[{"preset_id": "41", "beats": 6}]], "lanes_group_ids": [["5"]], "advance_mode": "beats", "steps": [{"preset_id": "41", "beats": 6}], "step_duration_ms": 3000, "simulated_bpm": 110, "sequence_transition": 500, "loop": true}, "11": {"name": "radiate chase", "profile_id": "1", "group_ids": [], "lanes": [[{"preset_id": "42", "beats": 12}, {"preset_id": "5", "beats": 4}]], "lanes_group_ids": [[]], "advance_mode": "beats", "steps": [{"preset_id": "42", "beats": 12}, {"preset_id": "5", "beats": 4}], "step_duration_ms": 3000, "simulated_bpm": 120, "sequence_transition": 500, "loop": true}}

src/controllers/device.py

@@ -8,7 +8,7 @@ from models.device import (
 )
 from models.group import Group
 from models.transport import get_current_sender
-from settings import Settings
+from settings import get_settings
 from util.brightness_combine import effective_brightness_for_mac
 from models.wifi_ws_clients import (
     normalize_tcp_peer_ip,
@@ -77,7 +77,7 @@ def _brightness_save_message_json(b_val: int) -> str:
 controller = Microdot()
 devices = Device()
 _group_registry = Group()
-_pi_settings = Settings()
+_pi_settings = get_settings()
 
 
 def _device_live_connected(dev_dict):

src/controllers/group.py

@@ -5,14 +5,14 @@ from models.group import Group
 from models.device import Device
 from models.transport import get_current_sender
 from models.wifi_ws_clients import normalize_tcp_peer_ip, send_json_line_to_ip
-from settings import Settings
+from settings import get_settings
 from util.brightness_combine import effective_brightness_for_mac
 import json
 
 controller = Microdot()
 groups = Group()
 devices = Device()
-_pi_settings = Settings()
+_pi_settings = get_settings()
 
 
 def _group_doc_visible_for_profile(doc, profile_id):

src/controllers/sequence.py

@@ -30,6 +30,7 @@ def get_current_profile_id(session=None):
 @with_session
 async def list_sequences(request, session):
     """List sequences for the current profile."""
+    sequences.load()
     current_profile_id = get_current_profile_id(session)
     if not current_profile_id:
         return json.dumps({}), 200, {"Content-Type": "application/json"}
@@ -97,6 +98,7 @@ async def import_sequence(request, session):
 @with_session
 async def get_sequence(request, session, id):
     """Get a specific sequence by ID (current profile only)."""
+    sequences.load()
     current_profile_id = get_current_profile_id(session)
     seq = sequences.read(id)
     if (
@@ -203,15 +205,46 @@ async def delete_sequence(request, session, id):
     return json.dumps({"error": "Sequence not found"}), 404
 
 
+@controller.post("/sync-phase")
+@with_session
+async def sync_sequence_beat_phase(request, session):
+    """Align beat counters while a sequence is playing (body: {\"mode\": \"step\"|\"pass\"})."""
+    _ = session
+    try:
+        data = request.json or {}
+    except Exception:
+        data = {}
+    if not isinstance(data, dict):
+        data = {}
+    mode = data.get("mode") or data.get("align") or "step"
+    try:
+        from util.sequence_playback import sync_beat_phase
+
+        if not await sync_beat_phase(str(mode)):
+            return (
+                json.dumps({"error": "No sequence is playing"}),
+                409,
+                {"Content-Type": "application/json"},
+            )
+        from util.audio_detector import anchor_shared_bar_phase
+
+        anchor_shared_bar_phase()
+        return json.dumps({"ok": True, "mode": str(mode).strip().lower()}), 200, {
+            "Content-Type": "application/json"
+        }
+    except Exception as e:
+        return json.dumps({"error": str(e)}), 500, {"Content-Type": "application/json"}
+
+
 @controller.post("/stop")
 @with_session
 async def stop_sequence_playback(request, session):
     """Stop server-driven zone sequence playback."""
     _ = request
     try:
-        from util.sequence_playback import stop
+        from util.sequence_playback import stop_playback
 
-        stop()
+        await stop_playback(clear_devices=True)
         return json.dumps({"ok": True}), 200, {"Content-Type": "application/json"}
     except Exception as e:
         return json.dumps({"error": str(e)}), 500, {"Content-Type": "application/json"}
@@ -251,8 +284,12 @@ async def play_sequence(request, session, id):
     try:
         from util.sequence_playback import start
 
-        await start(zone_id, str(id), str(current_profile_id), data if isinstance(data, dict) else None)
-        return json.dumps({"ok": True}), 200, {"Content-Type": "application/json"}
+        play_opts = data if isinstance(data, dict) else None
+        await start(zone_id, str(id), str(current_profile_id), play_opts)
+        from util.sequence_playback import pending_play_status
+
+        body = {"ok": True, **pending_play_status()}
+        return json.dumps(body), 200, {"Content-Type": "application/json"}
     except ValueError as e:
         return json.dumps({"error": str(e)}), 400, {"Content-Type": "application/json"}
     except RuntimeError as e:

src/controllers/settings.py

@@ -4,10 +4,10 @@ import json
 from microdot import Microdot, send_file
 
 from models import wifi_ws_clients
-from settings import Settings
+from settings import get_settings
 
 controller = Microdot()
-settings = Settings()
+settings = get_settings()
 
 @controller.get('')
 async def get_settings(request):
@@ -75,7 +75,21 @@ def _validate_global_brightness(value):
     return v
 
 
-@controller.put('/settings')
+def _validate_sequence_switch_wait(value):
+    s = str(value).strip().lower()
+    if s not in ("beat", "downbeat"):
+        raise ValueError("sequence_switch_wait must be beat or downbeat")
+    return s
+
+
+def _validate_audio_beat_phase_ms(value):
+    v = int(value)
+    if v < 0 or v > 500:
+        raise ValueError("audio_beat_phase_ms must be between 0 and 500")
+    return v
+
+
+@controller.put('')
 async def update_settings(request):
     """Update general settings."""
     try:
@@ -87,6 +101,10 @@ async def update_settings(request):
             elif key == 'global_brightness' and value is not None:
                 settings[key] = _validate_global_brightness(value)
                 global_brightness_changed = True
+            elif key == 'sequence_switch_wait' and value is not None:
+                settings[key] = _validate_sequence_switch_wait(value)
+            elif key == 'audio_beat_phase_ms' and value is not None:
+                settings[key] = _validate_audio_beat_phase_ms(value)
             else:
                 settings[key] = value
         settings.save()

src/controllers/zone.py

@@ -145,6 +145,7 @@ async def zone_content_fragment(request, session, id):
 @controller.get("")
 @with_session
 async def list_zones(request, session):
+    zones.load()
     profile_id = get_current_profile_id(session)
     current_zone_id = get_current_zone_id(request, session)
     zone_order = get_profile_zone_order(profile_id) if profile_id else []
@@ -213,6 +214,7 @@ async def set_current_zone(request, id):
 
 @controller.get("/<id>")
 async def get_zone(request, id):
+    zones.load()
     z = zones.read(id)
     if z:
         return json.dumps(z), 200, {"Content-Type": "application/json"}

src/main.py

@@ -10,7 +10,7 @@ import traceback
 from microdot import Microdot, send_file
 from microdot.websocket import with_websocket
 from microdot.session import Session
-from settings import Settings
+from settings import get_settings
 
 import controllers.preset as preset
 import controllers.profile as profile
@@ -159,8 +159,12 @@ async def _periodic_wifi_driver_hello_loop(settings, udp_holder) -> None:
     sock.setblocking(False)
     loop = asyncio.get_running_loop()
     try:
-        while True:
-            await asyncio.sleep(interval)
+        while not udp_holder.get("closing"):
+            slept = 0.0
+            while slept < interval and not udp_holder.get("closing"):
+                chunk = min(1.0, interval - slept)
+                await asyncio.sleep(chunk)
+                slept += chunk
             if udp_holder.get("closing"):
                 break
             try:
@@ -244,7 +248,7 @@ async def _send_bridge_wifi_channel(settings, sender):
 
 
 async def main(port=80):
-    settings = Settings()
+    settings = get_settings()
     print(settings)
     print("Starting")
 
@@ -377,7 +381,12 @@ async def main(port=80):
             audio_detector.start(device=device)
             from util.audio_run_persist import write_audio_run_state
 
-            write_audio_run_state(enabled=True, device=device)
+            write_audio_run_state(
+                enabled=True,
+                device=device,
+                device_override=str(payload.get("device_override") or ""),
+                device_select=str(payload.get("device_select") or ""),
+            )
             return {"ok": True, "status": audio_detector.status()}
         except Exception as e:
             return {"ok": False, "error": str(e)}, 500
@@ -391,6 +400,24 @@ async def main(port=80):
         write_audio_run_state(enabled=False)
         return {"ok": True, "status": audio_detector.status()}
 
+    @app.route('/api/audio/reset', methods=['POST'])
+    async def audio_reset(request):
+        """Clear beat/BPM tracking state without stopping the detector."""
+        _ = request
+        ok = audio_detector.reset_tracking()
+        if not ok:
+            return {"ok": False, "error": "Audio detector is not running"}, 409
+        return {"ok": True, "status": audio_detector.status()}
+
+    @app.route('/api/audio/anchor-bar', methods=['POST'])
+    async def audio_anchor_bar(request):
+        """Mark the current moment as bar beat 1 (downbeat)."""
+        _ = request
+        ok = audio_detector.anchor_bar_phase()
+        if not ok:
+            return {"ok": False, "error": "Audio detector is not running"}, 409
+        return {"ok": True, "status": audio_detector.status()}
+
     @app.route('/api/audio/status')
     async def audio_status(request):
         _ = request
@@ -426,6 +453,14 @@ async def main(port=80):
                 if bs > 0:
                     beat_readout = str(bs)
         st["beat_readout"] = beat_readout
+        from util.audio_run_persist import read_audio_run_state
+
+        st["beat_phase_ms"] = int(settings.get("audio_beat_phase_ms") or 0)
+        seq_wait = str(settings.get("sequence_switch_wait") or "beat").strip().lower()
+        if seq_wait not in ("beat", "downbeat"):
+            seq_wait = "beat"
+        st["sequence_switch_wait"] = seq_wait
+        st["audio_run"] = read_audio_run_state()
         return {"status": st}
 
     # Static file route
@@ -480,16 +515,30 @@ async def main(port=80):
     await _send_bridge_wifi_channel(settings, sender)
     _prime_wifi_outbound_driver_connections()
 
-    udp_holder = {"closing": False}
+    udp_holder = {"closing": False, "shutting_down": False}
     loop = asyncio.get_running_loop()
+    server_tasks: list[asyncio.Task] = []
 
     def _graceful_shutdown(*_args):
+        if udp_holder.get("shutting_down"):
+            raise SystemExit(0)
+        udp_holder["shutting_down"] = True
         print("[server] shutting down...")
         udp_holder["closing"] = True
         try:
             audio_detector.stop()
         except Exception:
             pass
+        try:
+            from util import sequence_playback as seq_pb
+
+            seq_pb.stop()
+            for attr in ("_pending_beat_task", "_sim_beat_task"):
+                t = getattr(seq_pb, attr, None)
+                if t is not None and not t.done():
+                    t.cancel()
+        except Exception:
+            pass
         u = udp_holder.get("sock")
         if u is not None:
             try:
@@ -498,7 +547,13 @@ async def main(port=80):
                 pass
         tcp_client_registry.cancel_all_driver_tasks()
         if getattr(app, "server", None) is not None:
-            app.shutdown()
+            try:
+                app.shutdown()
+            except Exception:
+                pass
+        for t in server_tasks:
+            if not t.done():
+                t.cancel()
 
     shutdown_handlers_registered = False
     try:
@@ -511,11 +566,21 @@ async def main(port=80):
 
         # Await HTTP + UDP discovery; bind failures (e.g. port 80 in use) surface here.
         try:
-            await asyncio.gather(
-                app.start_server(host="0.0.0.0", port=port),
-                _run_udp_discovery_server(udp_holder),
-                _periodic_wifi_driver_hello_loop(settings, udp_holder),
-            )
+            server_tasks[:] = [
+                asyncio.create_task(
+                    app.start_server(host="0.0.0.0", port=port), name="http"
+                ),
+                asyncio.create_task(
+                    _run_udp_discovery_server(udp_holder), name="udp"
+                ),
+                asyncio.create_task(
+                    _periodic_wifi_driver_hello_loop(settings, udp_holder),
+                    name="hello",
+                ),
+            ]
+            await asyncio.gather(*server_tasks)
+        except asyncio.CancelledError:
+            pass
         except OSError as e:
             if e.errno == errno.EADDRINUSE:
                 print(
@@ -540,6 +605,21 @@ async def main(port=80):
                 app.server = None
             except Exception:
                 pass
+        udp_holder["closing"] = True
+        for t in list(server_tasks):
+            if not t.done():
+                t.cancel()
+        if server_tasks:
+            await asyncio.gather(*server_tasks, return_exceptions=True)
+        pending = [
+            t
+            for t in asyncio.all_tasks(loop)
+            if t is not asyncio.current_task() and not t.done()
+        ]
+        for t in pending:
+            t.cancel()
+        if pending:
+            await asyncio.gather(*pending, return_exceptions=True)
         if shutdown_handlers_registered:
             for sig in (signal.SIGINT, signal.SIGTERM):
                 try:
@@ -549,5 +629,9 @@ async def main(port=80):
 
 if __name__ == "__main__":
     import os
+
     port = int(os.environ.get("PORT", 80))
-    asyncio.run(main(port=port))
+    try:
+        asyncio.run(main(port=port))
+    except KeyboardInterrupt:
+        print("[server] interrupted")

src/models/zone.py

@@ -22,7 +22,7 @@ class Zone(Model):
     """Preset layout row (stored in ``db/zone.json``); legacy storage was ``tab.json`` / Tab.
 
     Optional ``content_kind`` on a row: ``\"presets\"`` (preset tiles only) or ``\"sequences\"``
-    (sequence tiles only). Omitted or unknown => both (legacy behaviour).
+    (sequence tiles only). Legacy rows without ``content_kind`` are inferred on load.
     """
 
     def __init__(self):
@@ -43,6 +43,12 @@ class Zone(Model):
             if "preset_group_ids" not in doc or not isinstance(doc.get("preset_group_ids"), dict):
                 doc["preset_group_ids"] = {}
                 changed = True
+            if "sequence_ids" not in doc or not isinstance(doc.get("sequence_ids"), list):
+                doc["sequence_ids"] = []
+                changed = True
+            if not self._normalized_content_kind(doc):
+                doc["content_kind"] = self._infer_content_kind(doc)
+                changed = True
         if changed:
             self.save()
 
@@ -53,6 +59,41 @@ class Zone(Model):
         kind = doc.get("content_kind")
         return kind if kind in ("presets", "sequences") else None
 
+    @staticmethod
+    def _preset_ids_in_doc(doc):
+        if not isinstance(doc, dict):
+            return []
+        flat = doc.get("presets_flat")
+        if isinstance(flat, list):
+            return [str(x) for x in flat if x is not None and str(x).strip()]
+        presets = doc.get("presets")
+        if not isinstance(presets, list) or not presets:
+            return []
+        if isinstance(presets[0], str):
+            return [str(x) for x in presets if x is not None and str(x).strip()]
+        if isinstance(presets[0], list):
+            out = []
+            for row in presets:
+                if isinstance(row, list):
+                    out.extend(str(x) for x in row if x is not None and str(x).strip())
+            return out
+        return []
+
+    @classmethod
+    def _infer_content_kind(cls, doc):
+        kind = cls._normalized_content_kind(doc)
+        if kind:
+            return kind
+        seq_ids = [
+            str(x).strip()
+            for x in (doc.get("sequence_ids") or [])
+            if x is not None and str(x).strip()
+        ]
+        preset_ids = cls._preset_ids_in_doc(doc)
+        if seq_ids and not preset_ids:
+            return "sequences"
+        return "presets"
+
     def _enforce_content_kind_invariants(self, doc):
         """Presets-only zones hold no sequences; sequences-only hold no preset tiles."""
         kind = self._normalized_content_kind(doc)
@@ -95,7 +136,8 @@ class Zone(Model):
             return False
         patch = data if isinstance(data, dict) else {}
         self[id_str].update(patch)
-        self._enforce_content_kind_invariants(self[id_str])
+        if "content_kind" in patch:
+            self._enforce_content_kind_invariants(self[id_str])
         self.save()
         return True
 

src/settings.py

@@ -12,11 +12,15 @@ def _settings_path():
         return "settings.json"
 
 
+_settings_singleton: "Settings | None" = None
+
+
 class Settings(dict):
     SETTINGS_FILE = None  # Set in __init__ from _settings_path()
 
-    def __init__(self):
+    def __init__(self, *, quiet: bool = False):
         super().__init__()
+        self._quiet = quiet
         if Settings.SETTINGS_FILE is None:
             Settings.SETTINGS_FILE = _settings_path()
         self.load()  # Load settings from file during initialization
@@ -79,13 +83,22 @@ class Settings(dict):
         # Zone UI global brightness (0–255); shared across browsers/devices.
         if 'global_brightness' not in self:
             self['global_brightness'] = 255
+        # Sequence tile start: wait for beat or downbeat (server-owned).
+        if 'sequence_switch_wait' not in self:
+            self['sequence_switch_wait'] = 'beat'
+        elif str(self.get('sequence_switch_wait', '')).strip().lower() == 'phrase':
+            self['sequence_switch_wait'] = 'beat'
+        # Beat flash alignment delay (ms); applied by all UI clients polling audio status.
+        if 'audio_beat_phase_ms' not in self:
+            self['audio_beat_phase_ms'] = 0
 
     def save(self):
         try:
             j = json.dumps(self)
             with open(self.SETTINGS_FILE, 'w') as file:
                 file.write(j)
-            print("Settings saved successfully.")
+            if not getattr(self, "_quiet", False):
+                print("Settings saved successfully.")
         except Exception as e:
             print(f"Error saving settings: {e}")
 
@@ -96,9 +109,11 @@ class Settings(dict):
                 loaded_settings = json.load(file)
             self.update(loaded_settings)
             loaded_from_file = True
-            print("Settings loaded successfully.")
+            if not getattr(self, "_quiet", False):
+                print("Settings loaded successfully.")
         except Exception as e:
-            print(f"Error loading settings")
+            if not getattr(self, "_quiet", False):
+                print(f"Error loading settings: {e}")
             self.clear()
         finally:
             # Ensure defaults are set even if file exists but is missing keys
@@ -106,3 +121,18 @@ class Settings(dict):
             # Only save if file didn't exist or was invalid
             if not loaded_from_file:
                 self.save()
+
+
+def get_settings() -> Settings:
+    """Process-wide settings instance (avoid re-reading settings.json on every request)."""
+    global _settings_singleton
+    if _settings_singleton is None:
+        _settings_singleton = Settings()
+    return _settings_singleton
+
+
+def reload_settings() -> Settings:
+    """Re-read settings.json (e.g. after external file edit)."""
+    global _settings_singleton
+    _settings_singleton = Settings(quiet=True)
+    return _settings_singleton

src/util/audio_detector.py

@@ -4,6 +4,12 @@ import os
 import queue
 import threading
 import time
+from typing import Any
+
+
+_HOLDOVER_BPM_MIN = 30.0
+_HOLDOVER_BPM_MAX = 300.0
+_HOLDOVER_MAX_S = 300.0
 
 
 class AudioBeatDetector:
@@ -13,6 +19,11 @@ class AudioBeatDetector:
         self._stream = None
         self._running = False
         self._stop_event = threading.Event()
+        self._runtime = None
+        self._pending_reset = False
+        self._holdover_thread: threading.Thread | None = None
+        self._holdover_stop = threading.Event()
+        self._holdover_active = False
         self._status = {
             "running": False,
             "bpm": None,
@@ -20,6 +31,11 @@ class AudioBeatDetector:
             "beat_seq": 0,
             "beat_type": "unknown",
             "beat_type_confidence": 0.0,
+            "bar_beat": 1,
+            "beats_per_bar": 4,
+            "is_downbeat": False,
+            "phase_confidence": 0.0,
+            "bar_phase_readout": "1/4",
             "error": None,
             "device": None,
         }
@@ -100,6 +116,11 @@ class AudioBeatDetector:
                     "beat_seq": 0,
                     "beat_type": "unknown",
                     "beat_type_confidence": 0.0,
+                    "bar_beat": 1,
+                    "beats_per_bar": 4,
+                    "is_downbeat": False,
+                    "phase_confidence": 0.0,
+                    "bar_phase_readout": "1/4",
                     "error": None,
                     "device": device,
                 }
@@ -111,6 +132,7 @@ class AudioBeatDetector:
             self._thread.start()
 
     def stop(self):
+        self._stop_bpm_holdover()
         with self._lock:
             self._stop_event.set()
             t = self._thread
@@ -139,11 +161,159 @@ class AudioBeatDetector:
             self._running = False
             self._thread = None
             self._stream = None
+            self._pending_reset = False
             self._status["running"] = False
 
     def status(self):
         with self._lock:
-            return dict(self._status)
+            st = dict(self._status)
+            holdover = self._holdover_active
+        last = st.get("last_beat_ts")
+        if st.get("running") and last is not None and not holdover:
+            try:
+                if (time.time() - float(last)) > 4.0:
+                    st["bpm"] = None
+            except (TypeError, ValueError):
+                pass
+        return st
+
+    def _apply_tracking_reset_status(self) -> None:
+        """Refresh published status after a tracking reset (lock must be held)."""
+        bpb = max(1, int(self._status.get("beats_per_bar") or 4))
+        self._status.update(
+            {
+                "running": True,
+                "beat_type": "unknown",
+                "beat_type_confidence": 0.0,
+                "bar_beat": 1,
+                "is_downbeat": True,
+                "phase_confidence": 0.0,
+                "bar_phase_readout": f"1/{bpb}",
+            }
+        )
+
+    def _clamp_holdover_bpm(self, bpm: Any) -> float | None:
+        try:
+            v = float(bpm)
+        except (TypeError, ValueError):
+            return None
+        if not (_HOLDOVER_BPM_MIN <= v <= _HOLDOVER_BPM_MAX):
+            return None
+        return v
+
+    def _holdover_interval_s(self, bpm: float) -> float:
+        return 60.0 / max(_HOLDOVER_BPM_MIN, min(_HOLDOVER_BPM_MAX, float(bpm)))
+
+    def _stop_bpm_holdover(self) -> None:
+        with self._lock:
+            self._holdover_active = False
+        self._holdover_stop.set()
+        t = self._holdover_thread
+        if t and t.is_alive() and t is not threading.current_thread():
+            t.join(timeout=2.0)
+        with self._lock:
+            if self._holdover_thread is t:
+                self._holdover_thread = None
+
+    def _advance_holdover_bar_phase_locked(self) -> dict:
+        """Advance bar phase for one synthetic beat (lock must be held)."""
+        bpb = max(1, int(self._status.get("beats_per_bar") or 4))
+        prev = int(self._status.get("bar_beat") or 1)
+        bar_beat = (prev % bpb) + 1
+        is_downbeat = bar_beat == 1
+        bar_readout = f"{bar_beat}/{bpb}"
+        self._status["bar_beat"] = bar_beat
+        self._status["is_downbeat"] = is_downbeat
+        self._status["bar_phase_readout"] = bar_readout
+        return {
+            "bar_beat": bar_beat,
+            "beats_per_bar": bpb,
+            "is_downbeat": is_downbeat,
+            "bar_phase_readout": bar_readout,
+        }
+
+    def _emit_holdover_beat(self, bpm: float) -> None:
+        now = time.time()
+        with self._lock:
+            if not self._running or not self._holdover_active:
+                return
+            self._advance_holdover_bar_phase_locked()
+            self._status["last_beat_ts"] = now
+            self._status["bpm"] = float(bpm)
+            self._status["beat_type"] = "holdover"
+            self._status["beat_type_confidence"] = 0.0
+            self._status["beat_seq"] = int(self._status.get("beat_seq", 0)) + 1
+        try:
+            from util import sequence_playback as seq_pb
+
+            seq_pb.push_thread_beat()
+        except Exception as e:
+            print(f"[audio] holdover beat queue: {e}")
+
+    def _holdover_loop(self, bpm: float, started_at: float) -> None:
+        interval = self._holdover_interval_s(bpm)
+        while not self._holdover_stop.is_set():
+            with self._lock:
+                if not self._running or not self._holdover_active:
+                    return
+                if (time.time() - started_at) > _HOLDOVER_MAX_S:
+                    self._holdover_active = False
+                    return
+                last = self._status.get("last_beat_ts")
+            if last is not None:
+                try:
+                    delay = max(0.02, float(last) + interval - time.time())
+                except (TypeError, ValueError):
+                    delay = interval
+            else:
+                delay = interval
+            if self._holdover_stop.wait(delay):
+                return
+            self._emit_holdover_beat(bpm)
+
+    def _start_bpm_holdover(self, bpm: float) -> None:
+        bpm_v = self._clamp_holdover_bpm(bpm)
+        if bpm_v is None:
+            return
+        self._stop_bpm_holdover()
+        self._holdover_stop.clear()
+        started_at = time.time()
+        with self._lock:
+            self._holdover_active = True
+            self._holdover_thread = threading.Thread(
+                target=self._holdover_loop,
+                args=(bpm_v, started_at),
+                name="audio-bpm-holdover",
+                daemon=True,
+            )
+            t = self._holdover_thread
+        t.start()
+
+    def _process_pending_reset(self, runtime) -> None:
+        """Run ``reset_state`` on the audio thread (safe for aubio tempo)."""
+        with self._lock:
+            if not self._pending_reset:
+                return
+            self._pending_reset = False
+        try:
+            runtime.reset_state()
+            with self._lock:
+                self._apply_tracking_reset_status()
+        except Exception as e:
+            print(f"[audio] pending reset: {e}")
+
+    def reset_tracking(self) -> bool:
+        """Clear detector tempo history without stopping the input stream."""
+        holdover_bpm = None
+        with self._lock:
+            if not self._running or self._runtime is None:
+                return False
+            holdover_bpm = self._clamp_holdover_bpm(self._status.get("bpm"))
+            self._pending_reset = True
+            self._apply_tracking_reset_status()
+        if holdover_bpm is not None:
+            self._start_bpm_holdover(holdover_bpm)
+        return True
 
     def _set_error(self, msg):
         print(f"[audio] {msg}")
@@ -152,7 +322,28 @@ class AudioBeatDetector:
             self._status["running"] = False
             self._running = False
 
-    def _record_beat(self, bpm, beat_type="unknown", beat_type_confidence=0.0):
+    def anchor_bar_phase(self) -> bool:
+        """Mark the current moment as bar beat 1 (downbeat), e.g. after manual sync."""
+        with self._lock:
+            rt = self._runtime
+        if rt is None:
+            return False
+        try:
+            rt.anchor_bar_phase(time.time())
+            with self._lock:
+                self._status["bar_beat"] = 1
+                self._status["is_downbeat"] = True
+                self._status["bar_phase_readout"] = f"1/{int(self._status.get('beats_per_bar') or 4)}"
+                self._status["phase_confidence"] = max(
+                    float(self._status.get("phase_confidence") or 0.0), 0.85
+                )
+            return True
+        except Exception as e:
+            print(f"[audio] anchor_bar_phase: {e}")
+            return False
+
+    def _record_beat(self, bpm, beat_type="unknown", beat_type_confidence=0.0, **phase_fields):
+        self._stop_bpm_holdover()
         now = time.time()
         with self._lock:
             self._status["last_beat_ts"] = now
@@ -160,6 +351,16 @@ class AudioBeatDetector:
             self._status["beat_type"] = beat_type
             self._status["beat_type_confidence"] = float(beat_type_confidence or 0.0)
             self._status["beat_seq"] = int(self._status.get("beat_seq", 0)) + 1
+            if phase_fields.get("bar_beat") is not None:
+                self._status["bar_beat"] = int(phase_fields["bar_beat"])
+            if phase_fields.get("beats_per_bar") is not None:
+                self._status["beats_per_bar"] = int(phase_fields["beats_per_bar"])
+            if phase_fields.get("is_downbeat") is not None:
+                self._status["is_downbeat"] = bool(phase_fields["is_downbeat"])
+            if phase_fields.get("phase_confidence") is not None:
+                self._status["phase_confidence"] = float(phase_fields["phase_confidence"])
+            if phase_fields.get("bar_phase_readout"):
+                self._status["bar_phase_readout"] = str(phase_fields["bar_phase_readout"])
         try:
             from util import sequence_playback as seq_pb
 
@@ -210,15 +411,17 @@ class AudioBeatDetector:
                 flux_weight=0.3,
                 threshold_multiplier=1.35,
                 ema_alpha=0.08,
-                min_ioi_ms=85.0,
+                min_ioi_ms=100.0,
                 bpm_window=8,
                 post_url="",
                 aubio_method="default",
-                aubio_threshold=0.12,
-                silence_gate_db=-58.0,
+                aubio_threshold=0.14,
+                beats_per_bar=4,
             )
             runtime = beat_mod.BeatDetectRuntime(args)
             runtime.setup(sample_rate=sample_rate)
+            with self._lock:
+                self._runtime = runtime
             hop_size = runtime.frame_size
 
             audio_q = queue.Queue(maxsize=64)
@@ -243,10 +446,12 @@ class AudioBeatDetector:
             stream.start()
             try:
                 while not self._stop_event.is_set():
+                    self._process_pending_reset(runtime)
                     try:
                         frame = audio_q.get(timeout=0.1)
                     except queue.Empty:
                         continue
+                    self._process_pending_reset(runtime)
                     if frame.shape[0] != hop_size:
                         if frame.shape[0] > hop_size:
                             frame = frame[:hop_size]
@@ -260,6 +465,11 @@ class AudioBeatDetector:
                         bpm,
                         beat_type=event.get("beat_type", "unknown"),
                         beat_type_confidence=event.get("beat_type_confidence", 0.0),
+                        bar_beat=event.get("bar_beat"),
+                        beats_per_bar=event.get("beats_per_bar"),
+                        is_downbeat=event.get("is_downbeat"),
+                        phase_confidence=event.get("phase_confidence"),
+                        bar_phase_readout=event.get("bar_phase_readout"),
                     )
             finally:
                 try:
@@ -280,6 +490,7 @@ class AudioBeatDetector:
             with self._lock:
                 self._running = False
                 self._status["running"] = False
+                self._runtime = None
 
 
 # Set from ``main`` so sequence playback can tell real audio from simulated beats.
@@ -299,3 +510,25 @@ def shared_beat_detector_running():
         return bool(d.status().get("running"))
     except Exception:
         return False
+
+
+def shared_beat_status_snapshot() -> dict:
+    """Thread-safe copy of live detector status, or {} if audio is off."""
+    d = _shared_beat_detector
+    if d is None:
+        return {}
+    try:
+        return dict(d.status())
+    except Exception:
+        return {}
+
+
+def anchor_shared_bar_phase() -> bool:
+    """Anchor bar phase on the shared detector (no-op if audio is off)."""
+    d = _shared_beat_detector
+    if d is None:
+        return False
+    try:
+        return bool(d.anchor_bar_phase())
+    except Exception:
+        return False

src/util/audio_run_persist.py

@@ -30,20 +30,64 @@ def read_audio_run_state() -> Dict[str, Any]:
     except (OSError, json.JSONDecodeError, TypeError):
         return {"enabled": False, "device": None}
     if not isinstance(raw, dict):
-        return {"enabled": False, "device": None}
+        return {
+            "enabled": False,
+            "device": None,
+            "device_override": "",
+            "device_select": "",
+        }
     enabled = bool(raw.get("enabled"))
     dev = raw.get("device", None)
-    return {"enabled": enabled, "device": dev}
+    return {
+        "enabled": enabled,
+        "device": dev,
+        "device_override": str(raw.get("device_override") or ""),
+        "device_select": str(raw.get("device_select") or ""),
+    }
 
 
-def write_audio_run_state(*, enabled: bool, device: Any = None) -> None:
-    """Write run intent. When ``enabled`` is false, keep ``device`` from the previous file for next start."""
+def write_audio_run_state(
+    *,
+    enabled: bool,
+    device: Any = None,
+    device_override: str | None = None,
+    device_select: str | None = None,
+) -> None:
+    """Write run intent. When ``enabled`` is false, keep device fields from the previous file."""
     path = _db_path()
     prev = read_audio_run_state()
     if enabled:
-        data = {"enabled": True, "device": device}
+        data = {
+            "enabled": True,
+            "device": device,
+            "device_override": (
+                str(device_override)
+                if device_override is not None
+                else str(prev.get("device_override") or "")
+            ),
+            "device_select": (
+                str(device_select)
+                if device_select is not None
+                else str(prev.get("device_select") or "")
+            ),
+        }
+        if device_select is None and device is not None:
+            data["device_select"] = str(device)
     else:
-        data = {"enabled": False, "device": prev.get("device")}
+        data = {
+            "enabled": False,
+            "device": prev.get("device"),
+            "device_override": (
+                str(device_override)
+                if device_override is not None
+                else str(prev.get("device_override") or "")
+            ),
+            "device_select": (
+                str(device_select)
+                if device_select is not None
+                else str(prev.get("device_select") or "")
+            ),
+        }
     try:
         os.makedirs(os.path.dirname(path), exist_ok=True)
         with open(path, "w", encoding="utf-8") as f:

src/util/beat_driver_route.py

@@ -299,6 +299,10 @@ def _apply_manual_beat_route_standalone_overlay(
         return
     names = [str(n).strip() for n in device_names if str(n).strip()]
     with _route_lock:
+        if _sequence_lane_covers_standalone_overlay(names, str(wire_preset_id).strip()):
+            _lane_manual.pop(-1, None)
+            _sync_public_beat_route_from_lane_table()
+            return
         _lane_manual[-1] = {
             "device_names": names,
             "wire_preset_id": str(wire_preset_id).strip(),
@@ -350,6 +354,11 @@ def set_sequence_manual_lane_route(
             "manual_beat_n": mn,
             "beat_counter": bc,
         }
+        overlay = _lane_manual.get(-1)
+        if overlay and _lane_route_targets_key(names, wid) == _lane_route_targets_key(
+            overlay.get("device_names") or [], str(overlay.get("wire_preset_id") or "")
+        ):
+            _lane_manual.pop(-1, None)
         _sync_public_beat_route_from_lane_table()
 
 
@@ -362,6 +371,49 @@ def clear_sequence_manual_lane_route(lane_index: int) -> None:
         _sync_public_beat_route_from_lane_table()
 
 
+def _lane_route_targets_key(device_names: List[str], wire_preset_id: str) -> Tuple[Tuple[str, ...], str]:
+    names = tuple(sorted({str(n).strip() for n in (device_names or []) if str(n).strip()}))
+    return names, str(wire_preset_id or "").strip()
+
+
+def _sequence_lane_covers_standalone_overlay(device_names: List[str], wire_preset_id: str) -> bool:
+    """True when a sequence lane (0..n) already routes the same device(s) and wire preset."""
+    key = _lane_route_targets_key(device_names, wire_preset_id)
+    for lane_key, entry in _lane_manual.items():
+        if not isinstance(lane_key, int) or lane_key < 0:
+            continue
+        other = _lane_route_targets_key(
+            entry.get("device_names") or [], str(entry.get("wire_preset_id") or "")
+        )
+        if other == key:
+            return True
+    return False
+
+
+def mark_manual_select_sent_for_targets(
+    device_names: List[str], wire_preset_id: str
+) -> None:
+    """A ``select`` was just sent for these targets; skip one duplicate on the next beat."""
+    key = _lane_route_targets_key(device_names, wire_preset_id)
+    with _route_lock:
+        for entry in _lane_manual.values():
+            if not isinstance(entry, dict):
+                continue
+            other = _lane_route_targets_key(
+                entry.get("device_names") or [], str(entry.get("wire_preset_id") or "")
+            )
+            if other == key:
+                entry["suppress_next_notify"] = True
+
+
+def mark_sequence_manual_lane_select_sent(lane_index: int) -> None:
+    """A ``select`` was just sent for this lane; skip one duplicate on the next beat."""
+    with _route_lock:
+        e = _lane_manual.get(lane_index)
+        if e is not None:
+            e["suppress_next_notify"] = True
+
+
 def sync_beat_route_from_push_sequence(
     sequence: List[Any],
     target_macs: Optional[List[str]] = None,
@@ -438,6 +490,7 @@ def sync_beat_route_from_push_sequence(
             )
         else:
             _apply_manual_beat_route(device_names, wire_preset_id, preset_body)
+        mark_manual_select_sent_for_targets(device_names, wire_preset_id)
         return
 
     wire_id, body = _single_manual_wire_preset(merged_presets)
@@ -547,6 +600,7 @@ def notify_beat_detected() -> None:
         if not _lane_manual:
             return
         work = []
+        seen_targets: Set[Tuple[Tuple[str, ...], str]] = set()
         for key in sorted(_lane_manual.keys()):
             e = _lane_manual[key]
             names = e.get("device_names") or []
@@ -555,6 +609,8 @@ def notify_beat_detected() -> None:
             pattern = str(e.get("pattern") or "")
             if pattern and not _pattern_supports_manual(pattern):
                 continue
+            if e.pop("suppress_next_notify", False):
+                continue
             try:
                 n = int(e.get("manual_beat_n") or 1)
             except (TypeError, ValueError):
@@ -564,7 +620,12 @@ def notify_beat_detected() -> None:
             c = int(e["beat_counter"])
             if (c - 1) % n != 0:
                 continue
-            work.append((list(names), str(e.get("wire_preset_id") or "2")))
+            wire = str(e.get("wire_preset_id") or "2")
+            target_key = _lane_route_targets_key(names, wire)
+            if target_key in seen_targets:
+                continue
+            seen_targets.add(target_key)
+            work.append((list(names), wire))
         if work:
             _preset_session_beats += 1
     if not work:

src/util/sequence_playback.py

@@ -24,6 +24,16 @@ _sim_beat_token = 0
 _beat_run: Optional[Dict[str, Any]] = None
 _beat_run_lock = threading.Lock()
 
+_pending_play: Optional[Dict[str, Any]] = None
+_pending_play_lock = threading.Lock()
+_pending_beat_task: Optional[asyncio.Task] = None
+_pending_beat_token = 0
+_last_thread_beat_phase: Dict[str, Any] = {
+    "is_downbeat": True,
+    "bar_beat": 1,
+}
+_sim_beat_counter = 0
+
 
 def _norm_mac(raw: Any) -> Optional[str]:
     from models.device import normalize_mac
@@ -299,21 +309,6 @@ def _resolve_colors_with_palette_refs(
     return out
 
 
-def _ordered_unique_preset_ids_from_lanes(lanes: List[List[Dict[str, Any]]]) -> List[str]:
-    seen: set = set()
-    out: List[str] = []
-    for lane in lanes:
-        for step in lane:
-            if not isinstance(step, dict):
-                continue
-            pid = str(step.get("preset_id") or "").strip()
-            if not pid or pid in seen:
-                continue
-            seen.add(pid)
-            out.append(pid)
-    return out
-
-
 def _display_preset_for_step(
     preset_id: str,
     presets_map: Dict[str, Any],
@@ -348,6 +343,129 @@ def _preset_inner_from_display_preset(display_preset: Dict[str, Any]) -> Dict[st
     return inner
 
 
+def _ordered_unique_preset_ids_in_lane(lane: List[Dict[str, Any]]) -> List[str]:
+    seen: set = set()
+    out: List[str] = []
+    for step in lane:
+        if not isinstance(step, dict):
+            continue
+        pid = str(step.get("preset_id") or "").strip()
+        if not pid or pid in seen:
+            continue
+        seen.add(pid)
+        out.append(pid)
+    return out
+
+
+def _resolve_lane_device_names(lane_index: int, ctx: Dict[str, Any]) -> List[str]:
+    """Device names for one lane (lane groups / whole zone), after lane partition."""
+    lanes: List[List[Dict[str, Any]]] = ctx["lanes"]
+    sequence_doc: Dict[str, Any] = ctx["sequence_doc"]
+    zone_doc: Dict[str, Any] = ctx["zone_doc"]
+    devices = ctx["devices"]
+    groups = ctx["groups"]
+    num_lanes = int(ctx["num_lanes"])
+    lane = lanes[lane_index] if 0 <= lane_index < len(lanes) else []
+    if not lane:
+        return []
+    gids = _group_ids_for_lane_step(sequence_doc, lane[0], lane_index, num_lanes)
+    device_names = _resolve_step_device_names(
+        zone_doc, gids, devices, groups, sequence_doc=sequence_doc
+    )
+    return _split_device_names_for_lane(
+        device_names,
+        lane_index,
+        num_lanes,
+        partition_shared_zone=not _lane_has_non_empty_lanes_group_ids(sequence_doc, lane_index),
+    )
+
+
+def _build_lane_wire_presets_map(lane_index: int, ctx: Dict[str, Any]) -> Dict[str, Any]:
+    """All preset wire bodies for one lane, keyed by preset id."""
+    lanes: List[List[Dict[str, Any]]] = ctx["lanes"]
+    presets_map: Dict[str, Any] = ctx["presets_map"]
+    palette_colors: List[Any] = ctx["palette_colors"]
+    lane = lanes[lane_index] if 0 <= lane_index < len(lanes) else []
+    inner_by_wire: Dict[str, Any] = {}
+    for pid in _ordered_unique_preset_ids_in_lane(lane):
+        disp = _display_preset_for_step(pid, presets_map, palette_colors)
+        if not disp:
+            continue
+        inner_by_wire[str(pid)] = _preset_inner_from_display_preset(disp)
+    return inner_by_wire
+
+
+async def _prime_lane(lane_index: int, ctx: Dict[str, Any]) -> None:
+    """Upload all lane presets and select step 0 in one message (driver applies presets before select)."""
+    from models.transport import get_current_sender
+    from util.beat_driver_route import (
+        clear_sequence_manual_lane_route,
+        mark_sequence_manual_lane_select_sent,
+        set_sequence_manual_lane_route,
+    )
+    from util.driver_delivery import deliver_json_messages
+
+    lanes: List[List[Dict[str, Any]]] = ctx["lanes"]
+    presets_map: Dict[str, Any] = ctx["presets_map"]
+    palette_colors: List[Any] = ctx["palette_colors"]
+    lane_steps = lanes[lane_index] if 0 <= lane_index < len(lanes) else []
+    if not lane_steps:
+        return
+
+    inner_by_wire = _build_lane_wire_presets_map(lane_index, ctx)
+    if not inner_by_wire:
+        return
+
+    step0 = lane_steps[0]
+    preset_id = str(step0.get("preset_id") or "").strip()
+    if not preset_id:
+        return
+    display_preset = _display_preset_for_step(preset_id, presets_map, palette_colors)
+    if not display_preset:
+        return
+
+    device_names = _resolve_lane_device_names(lane_index, ctx)
+    macs = _device_names_to_macs(device_names, ctx["devices"])
+    if not macs:
+        return
+
+    sender = get_current_sender()
+    if not sender:
+        raise RuntimeError("Transport not configured")
+
+    zone_doc = ctx.get("zone_doc") if isinstance(ctx.get("zone_doc"), dict) else {}
+    devices_model = ctx["devices"]
+    wire = str(preset_id)
+    auto = _coerce_auto(display_preset)
+    sel: Dict[str, Any] = {}
+    for n in device_names:
+        if n:
+            sel[str(n)] = [wire]
+
+    delay_s = 0.05
+    for mac in macs:
+        body: Dict[str, Any] = {"v": "1", "presets": dict(inner_by_wire)}
+        if sel:
+            body["select"] = sel
+        msg = json.dumps(body, separators=(",", ":"))
+        await deliver_json_messages(sender, [msg], [mac], devices_model, delay_s=delay_s)
+
+    if auto:
+        clear_sequence_manual_lane_route(lane_index)
+    else:
+        inner = _preset_inner_from_display_preset(display_preset)
+        set_sequence_manual_lane_route(lane_index, device_names, wire, inner)
+        mark_sequence_manual_lane_select_sent(lane_index)
+
+
+async def _prime_all_lanes(ctx: Dict[str, Any]) -> None:
+    """One-shot preset upload + first-step select per lane (to each lane's groups)."""
+    for i in range(int(ctx["num_lanes"])):
+        await _prime_lane(i, ctx)
+    ctx["_presets_delivered"] = True
+    ctx["_sequence_primed"] = True
+
+
 def _parse_zone_brightness_value(zone_doc: Any) -> int:
     """Zone slider value stored on the zone row (0–255); default 255 if unset."""
     from util.brightness_combine import clamp255
@@ -363,37 +481,33 @@ def _parse_zone_brightness_value(zone_doc: Any) -> int:
         return 255
 
 
-def _inner_wire_b_with_sequence_zone_brightness(
-    inner: Dict[str, Any],
-    zone_doc: Dict[str, Any],
-    *,
-    target_mac: Optional[str],
-    settings_obj: Any,
-    groups_model: Any,
-    devices_model: Any,
-) -> Dict[str, Any]:
-    """Combine preset wire ``b`` with zone brightness (and global/group/device when ``target_mac`` is set)."""
-    from util.brightness_combine import (
-        clamp255,
-        multiply_brightness_factors,
-        effective_brightness_for_mac,
-    )
+async def _deliver_zone_brightness_for_sequence(ctx: Dict[str, Any]) -> None:
+    """Apply zone/global/group/device brightness like the zone slider (not inside preset ``b``)."""
+    from models.transport import get_current_sender
+    from util.brightness_combine import effective_brightness_for_mac
+    from util.driver_delivery import deliver_json_messages
 
-    out = dict(inner)
-    base = clamp255(out.get("b", 127))
+    sender = get_current_sender()
+    if not sender:
+        return
+    macs = _union_macs_for_sequence(ctx)
+    if not macs:
+        return
+    zone_doc = ctx.get("zone_doc") if isinstance(ctx.get("zone_doc"), dict) else {}
     zb = _parse_zone_brightness_value(zone_doc)
-    if target_mac and settings_obj is not None and groups_model is not None and devices_model is not None:
+    settings_obj = ctx.get("settings")
+    groups_model = ctx.get("groups")
+    devices_model = ctx.get("devices")
+    for mac in macs:
         eff = effective_brightness_for_mac(
             settings_obj,
             groups_model,
             devices_model,
-            target_mac,
+            mac,
             zone_brightness=zb,
         )
-        out["b"] = multiply_brightness_factors([base, eff])
-    else:
-        out["b"] = multiply_brightness_factors([base, zb])
-    return out
+        msg = json.dumps({"v": "1", "b": eff, "save": True}, separators=(",", ":"))
+        await deliver_json_messages(sender, [msg], [mac], devices_model, delay_s=0.05)
 
 
 def _device_names_to_macs(device_names: List[str], devices: Any) -> List[str]:
@@ -455,52 +569,21 @@ def _union_macs_for_sequence(ctx: Dict[str, Any]) -> List[str]:
     return list(z_macs)
 
 
-def _build_sequence_wire_presets_map(ctx: Dict[str, Any]) -> Dict[str, Any]:
-    lanes: List[List[Dict[str, Any]]] = ctx["lanes"]
-    presets_map: Dict[str, Any] = ctx["presets_map"]
-    palette_colors: List[Any] = ctx["palette_colors"]
-    inner_by_wire: Dict[str, Any] = {}
-    for pid in _ordered_unique_preset_ids_from_lanes(lanes):
-        disp = _display_preset_for_step(pid, presets_map, palette_colors)
-        if not disp:
-            continue
-        inner_by_wire[str(pid)] = _preset_inner_from_display_preset(disp)
-    return inner_by_wire
-
-
-async def _deliver_sequence_presets_bulk(ctx: Dict[str, Any]) -> None:
-    """Push all preset definitions used in the sequence once; step advances use select (auto) only."""
-    from models.transport import get_current_sender
-    from util.driver_delivery import deliver_json_messages
-
-    inner_by_wire = _build_sequence_wire_presets_map(ctx)
-    ctx["_sequence_wire_presets"] = inner_by_wire
-    if not inner_by_wire:
-        return
-    sender = get_current_sender()
-    if not sender:
-        raise RuntimeError("Transport not configured")
-    macs = _union_macs_for_sequence(ctx)
-    if not macs:
-        return
-    zone_doc = ctx.get("zone_doc") if isinstance(ctx.get("zone_doc"), dict) else {}
-    settings_obj = ctx.get("settings")
-    groups_model = ctx.get("groups")
-    devices_model = ctx.get("devices")
-    delay_s = 0.05
-    for mac in macs:
-        adjusted: Dict[str, Any] = {}
-        for wire_pid, inner in inner_by_wire.items():
-            adjusted[wire_pid] = _inner_wire_b_with_sequence_zone_brightness(
-                inner,
-                zone_doc,
-                target_mac=mac,
-                settings_obj=settings_obj,
-                groups_model=groups_model,
-                devices_model=devices_model,
-            )
-        msg = json.dumps({"v": "1", "presets": adjusted}, separators=(",", ":"))
-        await deliver_json_messages(sender, [msg], [mac], devices_model, delay_s=delay_s)
+def _coerce_loop(sequence_doc: Dict[str, Any]) -> bool:
+    raw = sequence_doc.get("loop", sequence_doc.get("sequence_loop", True))
+    if isinstance(raw, bool):
+        return raw
+    if raw is None:
+        return True
+    if isinstance(raw, int):
+        return raw != 0
+    if isinstance(raw, str):
+        lo = raw.strip().lower()
+        if lo in ("false", "0", "no", "off"):
+            return False
+        if lo in ("true", "1", "yes", "on"):
+            return True
+    return True
 
 
 def _coerce_auto(preset: Dict[str, Any]) -> bool:
@@ -533,119 +616,17 @@ def _load_palette_colors(profile_id: str) -> List[Any]:
     return Palette().read(str(pid)) or []
 
 
-async def _deliver_preset_for_devices(
-    preset_id: str,
-    preset_doc: Dict[str, Any],
-    device_names: List[str],
-    devices: Any,
-    *,
-    lane_index: Optional[int] = None,
-    zone_doc: Optional[Dict[str, Any]] = None,
-    settings_obj: Any = None,
-    groups_model: Any = None,
-) -> None:
-    from models.transport import get_current_sender
-    from util.driver_delivery import deliver_json_messages
-    from util.beat_driver_route import sync_beat_route_from_push_sequence
-    from util.espnow_message import build_preset_dict
-
-    sender = get_current_sender()
-    if not sender:
-        raise RuntimeError("Transport not configured")
-
-    macs: List[str] = []
-    seen: set = set()
-    for nm in device_names:
-        key = str(nm).strip()
-        if not key:
-            continue
-        m = None
-        for did in devices.list():
-            doc = devices.read(did) or {}
-            if str(doc.get("name") or "").strip() == key:
-                m = _norm_mac(did)
-                break
-        if not m and key.startswith("led-"):
-            m = _norm_mac(key[4:])
-        if m and m not in seen:
-            seen.add(m)
-            macs.append(m)
-    if not macs:
-        return
-
-    body = dict(preset_doc)
-    auto = _coerce_auto(body)
-    inner_base = build_preset_dict(body)
-    mb = body.get("manual_beat_n", body.get("manualBeatN"))
-    if mb is not None:
-        try:
-            n = int(mb)
-            if 1 <= n <= 64:
-                inner_base["manual_beat_n"] = n
-        except (TypeError, ValueError):
-            pass
-    wire = str(preset_id)
-    zone_use = zone_doc if isinstance(zone_doc, dict) else {}
-
-    sel_append: Optional[Dict[str, Any]] = None
-    if auto and device_names:
-        sel: Dict[str, Any] = {}
-        for n in device_names:
-            if n:
-                sel[str(n)] = [wire]
-        if sel:
-            sel_append = {"v": "1", "select": sel}
-
-    for mac in macs:
-        inner = _inner_wire_b_with_sequence_zone_brightness(
-            inner_base,
-            zone_use,
-            target_mac=mac,
-            settings_obj=settings_obj,
-            groups_model=groups_model,
-            devices_model=devices,
-        )
-        seq_list: List[Dict[str, Any]] = [{"v": "1", "presets": {wire: inner}}]
-        if sel_append:
-            seq_list.append(dict(sel_append))
-        messages = [json.dumps(x, separators=(",", ":")) for x in seq_list]
-        await deliver_json_messages(sender, messages, [mac], devices, delay_s=0.05)
-
-    if not auto:
-        manual_inner = _inner_wire_b_with_sequence_zone_brightness(
-            inner_base,
-            zone_use,
-            target_mac=macs[0] if len(macs) == 1 else None,
-            settings_obj=settings_obj,
-            groups_model=groups_model,
-            devices_model=devices,
-        )
-        if lane_index is not None:
-            from util.beat_driver_route import set_sequence_manual_lane_route
-
-            set_sequence_manual_lane_route(lane_index, device_names, wire, manual_inner)
-        else:
-            seq_one = [{"v": "1", "presets": {wire: manual_inner}}]
-            if sel_append:
-                seq_one.append(dict(sel_append))
-            sync_beat_route_from_push_sequence(
-                seq_one, target_macs=macs, preserve_parallel_lane_routes=True
-            )
-
-
 async def _send_lane(
     lane_index: int,
     st: Dict[str, Any],
     ctx: Dict[str, Any],
 ) -> None:
+    """Apply the current step (select or manual route). Presets must already be on devices."""
     lanes: List[List[Dict[str, Any]]] = ctx["lanes"]
     sequence_doc: Dict[str, Any] = ctx["sequence_doc"]
     presets_map: Dict[str, Any] = ctx["presets_map"]
-    zone_doc: Dict[str, Any] = ctx["zone_doc"]
-    devices = ctx["devices"]
-    groups = ctx["groups"]
     palette_colors: List[Any] = ctx["palette_colors"]
-    num_lanes = ctx["num_lanes"]
+    devices = ctx["devices"]
 
     if st.get("done"):
         return
@@ -660,14 +641,14 @@ async def _send_lane(
     display_preset = _display_preset_for_step(preset_id, presets_map, palette_colors)
     if not display_preset:
         return
-    gids = _group_ids_for_lane_step(sequence_doc, step, lane_index, num_lanes)
+    gids = _group_ids_for_lane_step(sequence_doc, step, lane_index, int(ctx["num_lanes"]))
     device_names = _resolve_step_device_names(
-        zone_doc, gids, devices, groups, sequence_doc=sequence_doc
+        ctx["zone_doc"], gids, devices, ctx["groups"], sequence_doc=sequence_doc
     )
     device_names = _split_device_names_for_lane(
         device_names,
         lane_index,
-        num_lanes,
+        int(ctx["num_lanes"]),
         partition_shared_zone=not _lane_has_non_empty_lanes_group_ids(sequence_doc, lane_index),
     )
     if gids and not device_names:
@@ -676,6 +657,7 @@ async def _send_lane(
     from models.transport import get_current_sender
     from util.beat_driver_route import (
         clear_sequence_manual_lane_route,
+        mark_sequence_manual_lane_select_sent,
         set_sequence_manual_lane_route,
     )
     from util.driver_delivery import deliver_json_messages
@@ -688,44 +670,29 @@ async def _send_lane(
     if not macs:
         return
 
-    bulk = ctx.get("_sequence_wire_presets")
-    if isinstance(bulk, dict) and bulk:
-        auto = _coerce_auto(display_preset)
+    wire = str(preset_id)
+    auto = _coerce_auto(display_preset)
+    if auto:
+        clear_sequence_manual_lane_route(lane_index)
+        sel: Dict[str, Any] = {}
+        for n in device_names:
+            if n:
+                sel[str(n)] = [wire]
+        if not sel:
+            return
+        msg = json.dumps({"v": "1", "select": sel}, separators=(",", ":"))
+        await deliver_json_messages(sender, [msg], macs, devices, delay_s=0.05)
+    else:
         inner = _preset_inner_from_display_preset(display_preset)
-        zone_use = ctx.get("zone_doc") if isinstance(ctx.get("zone_doc"), dict) else {}
-        inner = _inner_wire_b_with_sequence_zone_brightness(
-            inner,
-            zone_use,
-            target_mac=macs[0] if len(macs) == 1 else None,
-            settings_obj=ctx.get("settings"),
-            groups_model=ctx.get("groups"),
-            devices_model=devices,
-        )
-        wire = str(preset_id)
-        if auto:
-            clear_sequence_manual_lane_route(lane_index)
-            sel: Dict[str, Any] = {}
-            for n in device_names:
-                if n:
-                    sel[str(n)] = [wire]
-            if not sel:
-                return
+        set_sequence_manual_lane_route(lane_index, device_names, wire, inner)
+        sel: Dict[str, Any] = {}
+        for n in device_names:
+            if n:
+                sel[str(n)] = [wire]
+        if sel:
             msg = json.dumps({"v": "1", "select": sel}, separators=(",", ":"))
             await deliver_json_messages(sender, [msg], macs, devices, delay_s=0.05)
-        else:
-            set_sequence_manual_lane_route(lane_index, device_names, wire, inner)
-        return
-
-    await _deliver_preset_for_devices(
-        preset_id,
-        display_preset,
-        device_names,
-        devices,
-        lane_index=lane_index,
-        zone_doc=zone_doc,
-        settings_obj=ctx.get("settings"),
-        groups_model=groups,
-    )
+            mark_sequence_manual_lane_select_sent(lane_index)
 
 
 async def _send_all_lanes(ctx: Dict[str, Any]) -> None:
@@ -745,7 +712,7 @@ def _build_ctx(
 ) -> Optional[Dict[str, Any]]:
     from models.device import Device
     from models.group import Group
-    from settings import Settings
+    from settings import get_settings
 
     lanes = [x for x in _normalize_sequence_lanes(sequence_doc) if len(x) > 0]
     if not lanes:
@@ -764,9 +731,9 @@ def _build_ctx(
         "presets_map": presets_map,
         "devices": devices,
         "groups": groups,
-        "settings": Settings(),
+        "settings": get_settings(),
         "palette_colors": palette_colors,
-        "loop": True,
+        "loop": _coerce_loop(sequence_doc),
         "advance_mode": "beats",
     }
 
@@ -897,7 +864,294 @@ async def process_active_beat_advance() -> None:
     else:
         ctx["sequence_loop_beat"] = int(ctx.get("sequence_loop_beat", 0)) + 1
     if all(s.get("done") for s in lane_states):
-        stop()
+        await stop_playback(clear_devices=True)
+        return
+
+
+async def _clear_devices_after_sequence(ctx: Dict[str, Any]) -> None:
+    """Stop beat routing and clear driver presets for devices used by this sequence run."""
+    from models.transport import get_current_sender
+    from util.beat_driver_route import clear_sequence_manual_lane_route, update_beat_route
+    from util.driver_delivery import deliver_json_messages
+
+    num_lanes = int(ctx.get("num_lanes") or 0)
+    for i in range(num_lanes):
+        clear_sequence_manual_lane_route(i)
+    update_beat_route({"enabled": False})
+
+    sender = get_current_sender()
+    if not sender:
+        return
+    devices = ctx.get("devices")
+    macs = _union_macs_for_sequence(ctx)
+    if not macs:
+        return
+    msg = json.dumps({"v": "1", "clear_presets": True, "save": True}, separators=(",", ":"))
+    await deliver_json_messages(sender, [msg], macs, devices, delay_s=0.05)
+
+
+def _halt_playback_state() -> Optional[Dict[str, Any]]:
+    """Drop active run state and cancel simulated beats; return the previous ctx."""
+    global _beat_run, _sim_beat_task, _sim_beat_token
+    ctx: Optional[Dict[str, Any]] = None
+    with _beat_run_lock:
+        ctx = _beat_run
+        _beat_run = None
+        _sim_beat_token += 1
+    st = _sim_beat_task
+    _sim_beat_task = None
+    if st and not st.done():
+        st.cancel()
+    return ctx
+
+
+async def stop_playback(*, clear_devices: bool = True) -> None:
+    """Stop sequence playback; optionally clear presets on targeted devices."""
+    clear_pending_play()
+    ctx = _halt_playback_state()
+    if clear_devices and ctx:
+        await _clear_devices_after_sequence(ctx)
+
+
+def apply_beat_phase_sync(ctx: Dict[str, Any], mode: str) -> Tuple[bool, bool]:
+    """Align beat counters to music.
+
+    ``step`` (default): beat 1 of the current step on the next counted beat.
+    ``pass``: restart from step 1 of the sequence pass and re-apply presets.
+
+    Returns ``(ok, resend_lanes)`` — caller should ``await _send_all_lanes(ctx)`` when resend is true.
+    """
+    if not ctx:
+        return False, False
+    mode_norm = str(mode or "step").strip().lower()
+    lane_states: List[Dict[str, Any]] = ctx.get("lane_states") or []
+    if mode_norm in ("pass", "sequence", "restart"):
+        for st in lane_states:
+            st["stepIdx"] = 0
+            st["beatCount"] = 0
+            st["done"] = False
+        ctx["sequence_loop_beat"] = 0
+        return True, True
+    for st in lane_states:
+        if not st.get("done"):
+            st["beatCount"] = 0
+    return True, False
+
+
+async def sync_beat_phase(mode: str = "step") -> bool:
+    """Public entry: align active sequence playback to a musical phase."""
+    with _beat_run_lock:
+        ctx = _beat_run
+        if not ctx:
+            return False
+        ok, resend = apply_beat_phase_sync(ctx, mode)
+    if not ok:
+        return False
+    if resend:
+        await _send_all_lanes(ctx)
+    return True
+
+
+def _drain_beat_queue() -> None:
+    try:
+        while True:
+            _thread_beat_queue.get_nowait()
+    except queue.Empty:
+        pass
+
+
+def _reset_beat_side_effects() -> None:
+    """Clear manual routes and queued beats so startup cannot select before presets land."""
+    from util.beat_driver_route import update_beat_route
+
+    update_beat_route({"enabled": False})
+    _drain_beat_queue()
+
+
+def _sequence_switch_wait_from_settings() -> str:
+    try:
+        from settings import get_settings
+
+        raw = get_settings().get("sequence_switch_wait", "beat")
+        mode = _normalize_wait_for({"wait_for": raw}) or "beat"
+        if mode == "phrase":
+            return "beat"
+        return mode
+    except Exception:
+        return "beat"
+
+
+def _normalize_wait_for(play_options: Optional[Dict[str, Any]]) -> Optional[str]:
+    """``beat`` | ``downbeat`` | None (immediate)."""
+    if not isinstance(play_options, dict):
+        return None
+    raw = play_options.get("wait_for")
+    if raw is None:
+        raw = play_options.get("start_on")
+    if raw is None:
+        return None
+    s = str(raw).strip().lower()
+    if s in ("beat", "next_beat"):
+        return "beat"
+    if s in ("downbeat", "next_downbeat"):
+        return "downbeat"
+    return None
+
+
+def _play_options_without_wait(play_options: Optional[Dict[str, Any]]) -> Optional[Dict[str, Any]]:
+    if not isinstance(play_options, dict):
+        return play_options
+    out = dict(play_options)
+    out.pop("wait_for", None)
+    out.pop("start_on", None)
+    return out
+
+
+def _cancel_pending_beat_waiter() -> None:
+    global _pending_beat_task, _pending_beat_token
+    _pending_beat_token += 1
+    t = _pending_beat_task
+    _pending_beat_task = None
+    if t and not t.done():
+        t.cancel()
+
+
+def clear_pending_play() -> None:
+    """Drop a queued sequence start (e.g. user stop)."""
+    global _pending_play
+    with _pending_play_lock:
+        _pending_play = None
+    _cancel_pending_beat_waiter()
+
+
+def pending_play_status() -> Dict[str, Any]:
+    with _pending_play_lock:
+        p = _pending_play
+    if not p:
+        return {"pending": False}
+    return {
+        "pending": True,
+        "wait_for": p.get("wait_for"),
+        "sequence_id": p.get("sequence_id"),
+        "zone_id": p.get("zone_id"),
+    }
+
+
+def _beat_phase_from_sources() -> Dict[str, Any]:
+    from util import audio_detector as ad_mod
+
+    if ad_mod.shared_beat_detector_running():
+        st = ad_mod.shared_beat_status_snapshot()
+        if st:
+            return dict(st)
+    return dict(_last_thread_beat_phase)
+
+
+def _beat_is_downbeat_from_sources() -> bool:
+    return bool(_beat_phase_from_sources().get("is_downbeat"))
+
+
+def _mark_simulated_beat_phase(*, beats_per_bar: int = 4) -> None:
+    global _sim_beat_counter, _last_thread_beat_phase
+    bpb = max(1, int(beats_per_bar))
+    _sim_beat_counter += 1
+    bar_beat = ((_sim_beat_counter - 1) % bpb) + 1
+    is_downbeat = bar_beat == 1
+    _last_thread_beat_phase = {
+        "bar_beat": bar_beat,
+        "is_downbeat": is_downbeat,
+    }
+
+
+def _queue_pending_start(
+    zone_id: str,
+    sequence_id: str,
+    profile_id: str,
+    play_options: Optional[Dict[str, Any]],
+    wait_for: str,
+    *,
+    bpm: float,
+) -> None:
+    global _pending_play
+    clear_pending_play()
+    with _pending_play_lock:
+        _pending_play = {
+            "zone_id": str(zone_id),
+            "sequence_id": str(sequence_id),
+            "profile_id": str(profile_id),
+            "play_options": _play_options_without_wait(play_options),
+            "wait_for": wait_for,
+        }
+    _ensure_pending_beat_waiter(bpm)
+
+
+def _ensure_pending_beat_waiter(bpm: float) -> None:
+    """When nothing is playing and audio is off, emit synthetic beats until pending starts."""
+    from util import audio_detector as ad_mod
+
+    if ad_mod.shared_beat_detector_running():
+        return
+    with _beat_run_lock:
+        if _beat_run:
+            return
+    try:
+        loop = asyncio.get_running_loop()
+    except RuntimeError:
+        return
+    global _pending_beat_task, _pending_beat_token
+    t = _pending_beat_task
+    if t and not t.done():
+        t.cancel()
+    _pending_beat_token += 1
+    my_tok = _pending_beat_token
+    _pending_beat_task = loop.create_task(_pending_beat_wait_loop(bpm, my_tok))
+
+
+async def _pending_beat_wait_loop(bpm: float, my_token: int) -> None:
+    from util import audio_detector as ad_mod
+
+    interval = 60.0 / max(30.0, min(300.0, float(bpm)))
+    while True:
+        with _pending_play_lock:
+            if _pending_beat_token != my_token or _pending_play is None:
+                return
+        if ad_mod.shared_beat_detector_running():
+            return
+        await asyncio.sleep(interval)
+        with _pending_play_lock:
+            if _pending_beat_token != my_token or _pending_play is None:
+                return
+        if ad_mod.shared_beat_detector_running():
+            return
+        _mark_simulated_beat_phase()
+        push_thread_beat()
+
+
+async def _try_consume_pending_play(*, is_downbeat: bool) -> bool:
+    global _pending_play
+    with _pending_play_lock:
+        pending = _pending_play
+        if not pending:
+            return False
+        wait_for = str(pending.get("wait_for") or "beat").strip().lower()
+        if wait_for == "downbeat" and not is_downbeat:
+            return False
+        _pending_play = None
+    _cancel_pending_beat_waiter()
+    await _start_immediate(
+        pending["zone_id"],
+        pending["sequence_id"],
+        pending["profile_id"],
+        pending.get("play_options"),
+    )
+    return True
+
+
+def stop() -> None:
+    """Stop server playback state without sending device clear (e.g. before starting another run)."""
+    clear_pending_play()
+    _halt_playback_state()
+    _reset_beat_side_effects()
 
 
 def push_thread_beat() -> None:
@@ -920,6 +1174,12 @@ async def beat_consumer_loop() -> None:
             from util.beat_driver_route import notify_beat_detected
 
             for _ in range(n):
+                phase = _beat_phase_from_sources()
+                is_down = bool(phase.get("is_downbeat"))
+                try:
+                    await _try_consume_pending_play(is_downbeat=is_down)
+                except Exception as e:
+                    print(f"[sequence-playback] pending start: {e}")
                 try:
                     await process_active_beat_advance()
                 except Exception as e:
@@ -981,20 +1241,10 @@ async def _simulated_beat_loop(ctx: Dict[str, Any], my_token: int, bpm: float) -
             return
         if ad_mod.shared_beat_detector_running():
             continue
+        _mark_simulated_beat_phase()
         push_thread_beat()
 
 
-def stop() -> None:
-    global _beat_run, _sim_beat_task, _sim_beat_token
-    with _beat_run_lock:
-        _beat_run = None
-        _sim_beat_token += 1
-    st = _sim_beat_task
-    _sim_beat_task = None
-    if st and not st.done():
-        st.cancel()
-
-
 def stop_if_playing_sequence(sequence_id: str) -> bool:
     """If zone sequence playback is running this sequence id, stop it (e.g. after save/delete)."""
     sid = str(sequence_id).strip()
@@ -1007,7 +1257,11 @@ def stop_if_playing_sequence(sequence_id: str) -> bool:
         cur = ctx.get("sequence_id")
         if cur is None or str(cur).strip() != sid:
             return False
-    stop()
+    try:
+        loop = asyncio.get_running_loop()
+        loop.create_task(stop_playback(clear_devices=True))
+    except RuntimeError:
+        stop()
     return True
 
 
@@ -1016,6 +1270,29 @@ async def start(
     sequence_id: str,
     profile_id: str,
     play_options: Optional[Dict[str, Any]] = None,
+) -> None:
+    """Start immediately, or queue until the next beat / downbeat (``wait_for`` in *play_options*)."""
+    from models.sequence import Sequence
+
+    seq_m = Sequence()
+    sequence_doc = seq_m.read(sequence_id)
+    if not sequence_doc or str(sequence_doc.get("profile_id")) != str(profile_id):
+        raise ValueError("sequence not found")
+    wait_for = _sequence_switch_wait_from_settings()
+    if wait_for:
+        bpm = _coerce_simulated_bpm(sequence_doc, play_options)
+        _queue_pending_start(
+            zone_id, sequence_id, profile_id, play_options, wait_for, bpm=bpm
+        )
+        return
+    await _start_immediate(zone_id, sequence_id, profile_id, play_options)
+
+
+async def _start_immediate(
+    zone_id: str,
+    sequence_id: str,
+    profile_id: str,
+    play_options: Optional[Dict[str, Any]] = None,
 ) -> None:
     global _beat_run, _sim_beat_task, _sim_beat_token
     from models.preset import Preset
@@ -1052,14 +1329,11 @@ async def start(
     ctx["zone_id"] = str(zone_id)
     ctx["sequence_loop_beat"] = 0
 
-    await _deliver_sequence_presets_bulk(ctx)
-
-    from util.beat_driver_route import update_beat_route
-
-    update_beat_route({"enabled": False})
+    _reset_beat_side_effects()
+    await _prime_all_lanes(ctx)
+    await _deliver_zone_brightness_for_sequence(ctx)
     with _beat_run_lock:
         _beat_run = ctx
-    await _send_all_lanes(ctx)
 
     bpm = _coerce_simulated_bpm(sequence_doc, play_options)
     loop = asyncio.get_running_loop()