diff --git a/src/models/zone.py b/src/models/zone.py
index 46f5bb2..173ffc4 100644
--- a/src/models/zone.py
+++ b/src/models/zone.py
@@ -134,7 +134,11 @@ class Zone(Model):
         id_str = str(id)
         if id_str not in self:
             return False
-        patch = data if isinstance(data, dict) else {}
+        patch = dict(data) if isinstance(data, dict) else {}
+        doc = self[id_str]
+        locked_kind = self._normalized_content_kind(doc) or self._infer_content_kind(doc)
+        if "content_kind" in patch:
+            patch["content_kind"] = locked_kind
         self[id_str].update(patch)
         if "content_kind" in patch:
             self._enforce_content_kind_invariants(self[id_str])
diff --git a/src/static/audio.js b/src/static/audio.js
index e4d144c..f5be613 100644
--- a/src/static/audio.js
+++ b/src/static/audio.js
@@ -1,5 +1,6 @@
 (() => {
   let pollTimer = null;
+  let audioDetectorRunning = false;
   let lastBeatSeq = 0;
   let lastLoggedSequenceBeatFractions = "";
   /** Prior poll had server zone sequence playback active (`status.sequence.active === true`). */
@@ -161,13 +162,37 @@
 
   function updateSequenceSyncControls(zoneSeqActive) {
     const topSync = el("audio-top-beat-sync");
-    if (topSync) topSync.disabled = !zoneSeqActive;
+    if (topSync) {
+      topSync.disabled = audioDetectorRunning && !zoneSeqActive;
+      topSync.title = !audioDetectorRunning
+        ? "Start beat detection"
+        : zoneSeqActive
+          ? "Sync step to music (S)"
+          : "Beat detection running";
+    }
     const modalBeat = el("audio-modal-beat-readout");
     if (modalBeat) modalBeat.disabled = !zoneSeqActive;
     const passBtn = el("audio-sync-pass-btn");
     if (passBtn) passBtn.disabled = !zoneSeqActive;
   }
 
+  async function handleTopBpmButtonClick() {
+    if (!audioDetectorRunning) {
+      try {
+        await startAudio();
+      } catch (e) {
+        console.error("audio start failed", e);
+        alert("Failed to start audio input. Check mic permissions.");
+      }
+      return;
+    }
+    try {
+      await syncSequenceBeatPhase("step");
+    } catch (e) {
+      console.warn("sequence beat sync failed", e);
+    }
+  }
+
   async function syncSequenceBeatPhase(mode) {
     const res = await fetch("/sequences/sync-phase", {
       method: "POST",
@@ -250,6 +275,7 @@
 
   /** Stop detector and polling; does not clear “resume on load” prefs (used before restart). */
   async function stopAudioOnly() {
+    audioDetectorRunning = false;
     setTopBpmVisible(false);
     setNavResetVisible(false);
     clearBeatPhaseTimers();
@@ -285,6 +311,7 @@
           node.textContent = String(status.error).trim().slice(0, 120);
         }
         updateBeatReadoutDisplays({});
+        audioDetectorRunning = !!status.running;
         updateBpmDisplay(null);
         setTopBpmVisible(!!status.running);
         setNavResetVisible(!!status.running);
@@ -294,6 +321,7 @@
         }
         return;
       }
+      audioDetectorRunning = !!status.running;
       const zoneSeqActive = sequencePlaybackActiveFromStatus(status);
       setTopBpmVisible(!!status.running || zoneSeqActive);
       setNavResetVisible(!!status.running);
@@ -482,7 +510,12 @@
         }
       });
     };
-    bindSync(el("audio-top-beat-sync"), "step");
+    const topBpm = el("audio-top-beat-sync");
+    if (topBpm) {
+      topBpm.addEventListener("click", () => {
+        void handleTopBpmButtonClick();
+      });
+    }
     bindSync(el("audio-modal-beat-readout"), "step");
     bindSync(el("audio-sync-pass-btn"), "pass");
 
@@ -501,11 +534,14 @@
       const res = await fetch("/api/audio/status", { cache: "no-store" });
       const data = await res.json();
       const status = data?.status || {};
+      audioDetectorRunning = !!status.running;
       if (status.running && !pollTimer) {
         pollTimer = setInterval(pollStatus, 250);
         lastBeatSeq = Number(status.beat_seq || 0);
         prevZoneSequencePlaybackActive = sequencePlaybackActiveFromStatus(status);
         await pollStatus();
+      } else {
+        updateSequenceSyncControls(sequencePlaybackActiveFromStatus(status));
       }
     } catch (e) {
       console.warn("audio resume poll check failed", e);
diff --git a/src/static/zones.js b/src/static/zones.js
index ff366c1..2ab7f6d 100644
--- a/src/static/zones.js
+++ b/src/static/zones.js
@@ -310,8 +310,7 @@ async function computeZonePresetUnionTargets(zoneDoc) {
 }
 
 /**
- * Device names for one sequence step. Empty stepGroupIds => all zone tab devices (``names`` only).
- * Otherwise: lane groups intersected with that tab device list (not zone ``group_ids``).
+ * Device names for one sequence step. Only devices in checked lane groups (within the zone tab).
  */
 async function resolveSequenceStepDeviceNames(zone, stepGroupIds) {
     const zoneT = await computeZoneNamesTargets(zone);
@@ -321,7 +320,7 @@ async function resolveSequenceStepDeviceNames(zone, stepGroupIds) {
         ? stepGroupIds.map((x) => String(x).trim()).filter((x) => x.length > 0)
         : [];
     if (!gids.length) {
-        return names.slice();
+        return [];
     }
     const zoneMacSet = new Set(
         macs.map((m) => normalizeDeviceMac(m)).filter((m) => m.length === 12),
@@ -509,43 +508,15 @@ function effectiveZoneContentKind(zoneDoc) {
     return 'presets';
 }
 
-/** @returns {'presets' | 'sequences'} */
-function editModalContentKindSelected() {
-    const radio = document.querySelector('input[name="edit-zone-content-kind"]:checked');
-    return radio && radio.value === 'sequences' ? 'sequences' : 'presets';
-}
-
-function activeZoneContentKind(zoneDoc, zoneId) {
-    const modal = document.getElementById('edit-zone-modal');
-    const editingId = document.getElementById('edit-zone-id')?.value;
-    if (
-        modal &&
-        modal.classList.contains('active') &&
-        zoneId != null &&
-        zoneId !== '' &&
-        String(editingId) === String(zoneId)
-    ) {
-        return editModalContentKindSelected();
-    }
-    return effectiveZoneContentKind(zoneDoc);
-}
-
-/** True when the zone row has an explicit presets vs sequences type (not legacy inferred). */
-function zoneHasExplicitContentKind(zoneDoc) {
-    return normalizeZoneContentKind(zoneDoc) !== null;
-}
-
 /** @returns {boolean} */
 function zoneAllowsPresets(zoneDoc, zoneId) {
     void zoneId;
-    if (!zoneHasExplicitContentKind(zoneDoc)) return true;
     return effectiveZoneContentKind(zoneDoc) === 'presets';
 }
 
 /** @returns {boolean} */
 function zoneAllowsSequences(zoneDoc, zoneId) {
     void zoneId;
-    if (!zoneHasExplicitContentKind(zoneDoc)) return true;
     return effectiveZoneContentKind(zoneDoc) === 'sequences';
 }
 
@@ -623,7 +594,7 @@ function renderZonesList(tabs, tabOrder, currentZoneId) {
     for (const zoneId of tabOrder) {
         const zone = tabs[zoneId];
         if (zone) {
-            const activeClass = zoneId === currentZoneId ? 'active' : '';
+            const activeClass = String(zoneId) === String(currentZoneId) ? 'active' : '';
             const disp = zone.name || `Zone ${zoneId}`;
             html += `
                 <button class="zone-button ${activeClass}" 
@@ -1183,9 +1154,13 @@ async function openEditZoneModal(zoneId, zone) {
     renderZoneGroupsEditor(groupsEditor, window.__editTabGroupRows, groupsMap);
 
     const kind = effectiveZoneContentKind(tabData);
-    document.querySelectorAll('input[name="edit-zone-content-kind"]').forEach((radio) => {
-        radio.checked = radio.value === kind;
-    });
+    const typeLabel = document.getElementById('edit-zone-type-label');
+    if (typeLabel) {
+        typeLabel.textContent =
+            kind === 'sequences'
+                ? 'Zone type: Sequences (set when the zone was created)'
+                : 'Zone type: Presets (set when the zone was created)';
+    }
 
     if (modal) modal.classList.add("active");
     applyZoneContentKindEditModal(kind);
@@ -1196,13 +1171,11 @@ async function openEditZoneModal(zoneId, zone) {
 }
 
 // Update an existing zone (name, group list; devices come from groups only).
-async function updateZone(zoneId, name, groupRows, contentKind) {
+async function updateZone(zoneId, name, groupRows) {
     try {
         const gids = Array.isArray(groupRows)
             ? groupRows.map((r) => String(r.id || "").trim()).filter((x) => x.length > 0)
             : [];
-        const ck =
-            contentKind === 'sequences' || contentKind === 'presets' ? contentKind : 'presets';
         let existing = {};
         try {
             const cur = await fetch(`/zones/${encodeURIComponent(zoneId)}`, {
@@ -1215,6 +1188,7 @@ async function updateZone(zoneId, name, groupRows, contentKind) {
         } catch (_) {
             /* use empty existing */
         }
+        const lockedKind = effectiveZoneContentKind(existing);
         const response = await fetch(`/zones/${zoneId}`, {
             method: 'PUT',
             headers: {
@@ -1229,7 +1203,7 @@ async function updateZone(zoneId, name, groupRows, contentKind) {
                     existing.preset_group_ids && typeof existing.preset_group_ids === 'object'
                         ? existing.preset_group_ids
                         : {},
-                content_kind: ck,
+                content_kind: lockedKind,
             })
         });
         
@@ -1238,6 +1212,9 @@ async function updateZone(zoneId, name, groupRows, contentKind) {
             // Reload tabs list
             await loadZonesModal();
             await loadZones();
+            if (String(currentZoneId) === String(zoneId)) {
+                await loadZoneContent(zoneId);
+            }
             // Close modal
             document.getElementById('edit-zone-modal').classList.remove('active');
             return true;
@@ -1369,18 +1346,6 @@ document.addEventListener('DOMContentLoaded', () => {
         });
     }
     
-    document.querySelectorAll('input[name="edit-zone-content-kind"]').forEach((radio) => {
-        radio.addEventListener('change', async () => {
-            applyZoneContentKindEditModal(editModalContentKindSelected());
-            const zoneId = document.getElementById('edit-zone-id')?.value;
-            if (!zoneId) return;
-            await refreshEditTabPresetsUi(zoneId);
-            if (typeof window.refreshEditTabSequencesUi === 'function') {
-                await window.refreshEditTabSequencesUi(zoneId);
-            }
-        });
-    });
-
     // Set up edit zone form
     const editZoneForm = document.getElementById('edit-zone-form');
     if (editZoneForm) {
@@ -1394,7 +1359,7 @@ document.addEventListener('DOMContentLoaded', () => {
             const groupRows = window.__editTabGroupRows || [];
 
             if (zoneId && name) {
-                await updateZone(zoneId, name, groupRows, editModalContentKindSelected());
+                await updateZone(zoneId, name, groupRows);
                 editZoneForm.reset();
             }
         });
@@ -1441,6 +1406,8 @@ document.addEventListener('DOMContentLoaded', () => {
     });
 });
 
+window.selectZone = selectZone;
+
 // Export for use in other scripts
 window.zonesManager = {
     loadZones,
diff --git a/src/templates/index.html b/src/templates/index.html
index 9559514..19d17c9 100644
--- a/src/templates/index.html
+++ b/src/templates/index.html
@@ -119,10 +119,7 @@
                 <input type="hidden" id="edit-zone-id">
                 <label>Zone Name:</label>
                 <input type="text" id="edit-zone-name" placeholder="Enter zone name" required>
-                <div class="zone-content-kind-row muted-text">
-                    <label><input type="radio" name="edit-zone-content-kind" value="presets" checked> Presets</label>
-                    <label><input type="radio" name="edit-zone-content-kind" value="sequences"> Sequences</label>
-                </div>
+                <p id="edit-zone-type-label" class="zone-content-kind-row muted-text" aria-live="polite"></p>
                 <div id="edit-zone-block-groups">
                 <label class="zone-devices-label">Device groups on this zone</label>
                 <div id="edit-zone-groups-editor" class="zone-devices-editor"></div>