diff --git a/app/static/js/app.jsx b/app/static/js/app.jsx
index a0fe7da..fe90460 100644
--- a/app/static/js/app.jsx
+++ b/app/static/js/app.jsx
@@ -12380,12 +12380,20 @@ const App = () => {
   const updateActiveTracksRef = useCallback(updater => {
     const currentSessionTabs = sessionTabsRef.current;
     const currentActiveTab = activeTabRef.current;
-    const st = currentSessionTabs.find(s => s.id === currentActiveTab);
+    var st = currentSessionTabs.find(s => s.id === currentActiveTab);
     if (st) {
       setSessionTabs(prev => prev.map(s => s.id === currentActiveTab ? { ...s, tracks: updater(s.tracks), isDirty: true } : s));
-    } else {
-      setTracks(updater);
+      return;
     }
+    var pr = subTabsRef.current ? subTabsRef.current.find(s => s.id === currentActiveTab && s.type === 'PIANO_ROLL') : null;
+    if (pr && pr.parent_tab_id && pr.parent_tab_id.startsWith('session_')) {
+      var parentSt = currentSessionTabs.find(s => s.id === pr.parent_tab_id);
+      if (parentSt) {
+        setSessionTabs(prev => prev.map(s => s.id === pr.parent_tab_id ? { ...s, tracks: updater(s.tracks), isDirty: true } : s));
+        return;
+      }
+    }
+    setTracks(updater);
   }, []);
   const updateActiveTracks = updateActiveTracksRef;
 
diff --git a/app/static/js/app.precompiled.js b/app/static/js/app.precompiled.js
index 53b3814..a07c3ad 100644
--- a/app/static/js/app.precompiled.js
+++ b/app/static/js/app.precompiled.js
@@ -348,7 +348,7 @@ uploadToServer(file,trackId);// Decode locally for playback + analyze channels (
 const{audioBuffer:decodedBuffer,channelInfo}=await window.SonicAudio.decodeAudioFile(file);setTracks(prev=>prev.map(t=>t.id===trackId?{...t,name:file.name,buffer:decodedBuffer,channelInfo:channelInfo}:t));showToast(`Nạp file thành công: ${file.name} (${channelInfo.label})`,'success');}catch(err){showToast("Lỗi giải mã âm thanh. Định dạng file không tương thích.",'error');}};// ── Synth Generators ──
 const generateSynthToTrack=(trackId,type)=>{const sampleRate=44100;const duration=12.0;const context=getAudioContext();const frameCount=sampleRate*duration;const newBuffer=context.createBuffer(1,frameCount,sampleRate);const channelData=newBuffer.getChannelData(0);if(type==='kick'){for(let i=0;i<frameCount;i++){const t=i/sampleRate;const beatTime=t%0.5;const freq=120*Math.exp(-35*beatTime);channelData[i]=Math.sin(2*Math.PI*freq*beatTime)*Math.exp(-6*beatTime);}}else{const notes=[220.00,261.63,293.66,329.63,392.00];for(let i=0;i<frameCount;i++){const t=i/sampleRate;const noteIdx=Math.floor(t*2)%notes.length;const freq=notes[noteIdx];channelData[i]=Math.sin(2*Math.PI*freq*t)*0.25*(1.0-t%0.5/0.5);}}updateActiveTracks(prev=>prev.map(t=>t.id===trackId?{...t,name:`Demo_${type.toUpperCase()}.wav`,buffer:newBuffer}:t));showToast(`Đã nạp sóng âm tổng hợp: ${type.toUpperCase()}`,'success');};// ── Add Track ──
 const addNewTrack=()=>{const curTracks=activeTracks;const newId=(curTracks.length+1).toString();const colors=['#0f766e','#1d4ed8','#701a75','#a21caf','#b45309'];const selectColor=colors[curTracks.length%colors.length];updateActiveTracks(prev=>[...prev,{id:newId,name:`Track ${newId}`,buffer:null,startTime:0,volumeDb:0,pan:0,muted:false,solo:false,color:selectColor,markers:[],serverFileId:null,clips:[],sections:[],midiItems:[],isArmed:false,monitoringEnabled:true,inputSource:{deviceType:'NONE',deviceId:''}}]);showToast(`Đã thêm Track ${newId}.`,'info');setTimeout(()=>lucide.createIcons(),200);return newId;};// ── Update tracks in active context (main session or section tab) ──
-const updateActiveTracksRef=useCallback(updater=>{const currentSessionTabs=sessionTabsRef.current;const currentActiveTab=activeTabRef.current;const st=currentSessionTabs.find(s=>s.id===currentActiveTab);if(st){setSessionTabs(prev=>prev.map(s=>s.id===currentActiveTab?{...s,tracks:updater(s.tracks),isDirty:true}:s));}else{setTracks(updater);}},[]);const updateActiveTracks=updateActiveTracksRef;const toggleTrackArm=trackId=>{updateActiveTracks(prev=>prev.map(t=>{if(t.id!==trackId)return t;return{...t,isArmed:!t.isArmed};}));setTimeout(()=>lucide.createIcons(),50);};const toggleTrackMonitor=trackId=>{updateActiveTracks(prev=>prev.map(t=>{if(t.id!==trackId)return t;return{...t,monitoringEnabled:!t.monitoringEnabled};}));setTimeout(()=>lucide.createIcons(),50);};const updateTrackInputSource=(trackId,type,deviceId)=>{updateActiveTracks(prev=>prev.map(t=>{if(t.id!==trackId)return t;return{...t,inputSource:{deviceType:type,deviceId}};}));};// ── MIDI Export: tạo file MIDI từ tất cả tracks ──
+const updateActiveTracksRef=useCallback(updater=>{const currentSessionTabs=sessionTabsRef.current;const currentActiveTab=activeTabRef.current;var st=currentSessionTabs.find(s=>s.id===currentActiveTab);if(st){setSessionTabs(prev=>prev.map(s=>s.id===currentActiveTab?{...s,tracks:updater(s.tracks),isDirty:true}:s));return;}var pr=subTabsRef.current?subTabsRef.current.find(s=>s.id===currentActiveTab&&s.type==='PIANO_ROLL'):null;if(pr&&pr.parent_tab_id&&pr.parent_tab_id.startsWith('session_')){var parentSt=currentSessionTabs.find(s=>s.id===pr.parent_tab_id);if(parentSt){setSessionTabs(prev=>prev.map(s=>s.id===pr.parent_tab_id?{...s,tracks:updater(s.tracks),isDirty:true}:s));return;}}setTracks(updater);},[]);const updateActiveTracks=updateActiveTracksRef;const toggleTrackArm=trackId=>{updateActiveTracks(prev=>prev.map(t=>{if(t.id!==trackId)return t;return{...t,isArmed:!t.isArmed};}));setTimeout(()=>lucide.createIcons(),50);};const toggleTrackMonitor=trackId=>{updateActiveTracks(prev=>prev.map(t=>{if(t.id!==trackId)return t;return{...t,monitoringEnabled:!t.monitoringEnabled};}));setTimeout(()=>lucide.createIcons(),50);};const updateTrackInputSource=(trackId,type,deviceId)=>{updateActiveTracks(prev=>prev.map(t=>{if(t.id!==trackId)return t;return{...t,inputSource:{deviceType:type,deviceId}};}));};// ── MIDI Export: tạo file MIDI từ tất cả tracks ──
 const triggerMidiExport=()=>{const bpmNum=parseFloat(bpm)||120;const ppq=480;// Pulses Per Quarter Note
 const ticksPerBeat=ppq;const beatDuration=60/bpmNum;// Build MIDI tracks
 let midiTracks=[];let currentTrackNum=0;tracks.forEach(track=>{currentTrackNum++;const events=[];let hasNotes=false;// Collect MIDI events from midiItems
diff --git a/wiki.md b/wiki.md
index ce4d85d..7a16a89 100644
--- a/wiki.md
+++ b/wiki.md
@@ -538,3 +538,9 @@
 - **Các file ảnh hưởng:** `app/static/js/app.jsx`, `app/static/js/app.precompiled.js`
 - **Ghi chú/Test (nếu có):** `npm run build` pass. Ctrl+Click+Drag section/MIDI item → copy đến vị trí mới, item không bị selected.
 ---
+
+### [2026-07-28 08:12] Task: Sync instrument load methods từ MAIN vào SECTION-TAB PIANO_ROLL
+- **Tóm tắt thay đổi:** Fix `updateActiveTracksRef` — khi `activeTab` là PIANO_ROLL sub-tab có `parent_tab_id` trỏ đến SECTION-TAB, routing instrument update vào `setSessionTabs` thay vì `setTracks` (main). Trước đây đổi instrument trong PIANO_ROLL của SECTION-TAB ghi vào main tracks (vô hiệu). Cùng logic với `activeTracks` useMemo fix trước đó.
+- **Các file ảnh hưởng:** `app/static/js/app.jsx`, `app/static/js/app.precompiled.js`
+- **Ghi chú/Test (nếu có):** `npm run build` pass. Mở SECTION-TAB → PIANO_ROLL → Synth → chọn instrument → verify instrument được áp dụng cho section track (không phải main track).
+---