diff --git a/app/static/js/services/soundfontPlayer.js b/app/static/js/services/soundfontPlayer.js
index 95543ab..7a110dd 100644
--- a/app/static/js/services/soundfontPlayer.js
+++ b/app/static/js/services/soundfontPlayer.js
@@ -362,41 +362,29 @@
                 typeof velocity === 'number' ? (velocity > 1 ? velocity : velocity * 127) : 100
             )));
             var _origChannel = channel;
-            var ch = channel;
             var usedBank = 0, usedProg = 0;
             if (synthEngine) {
                 usedBank = synthEngine.soundfont_bank || 0;
                 usedProg = synthEngine.soundfont_program || 0;
-                if (ch === undefined) {
+                if (channel === undefined) {
                     var engKey = (synthEngine.soundfont_id || '') + ':' + usedBank + ':' + usedProg;
                     var mappedCh = _engineChMap[engKey];
                     if (mappedCh !== undefined) {
-                        ch = mappedCh;
+                        channel = mappedCh;
                     } else {
-                        ch = usedBank === 128 ? 9 : 0;
+                        channel = usedBank === 128 ? 9 : 0;
                     }
                 }
-                if (ch === undefined) ch = (usedBank === 128 ? 9 : 0);
-                var sfHandle = synthEngine.soundfont_id ? _sfHandleMap.get(synthEngine.soundfont_id) : undefined;
-                if (sfHandle !== undefined) {
-                    try {
-                        _fluidModule._fluid_synth_program_select(_synthPtr, ch, sfHandle, usedBank, usedProg);
-                    } catch (e) {}
-                } else {
-                    try { _fluidModule._fluid_synth_bank_select(_synthPtr, ch, usedBank); } catch (e) {}
-                    try { _fluidModule._fluid_synth_program_change(_synthPtr, ch, usedProg); } catch (e) {}
-                }
+                if (channel === undefined) channel = (usedBank === 128 ? 9 : 0);
             } else if (program !== undefined) {
                 usedProg = program;
-                if (ch === undefined) ch = 0;
-                try {
-                    _fluidModule._fluid_synth_program_change(_synthPtr, ch, usedProg);
-                } catch (e) {}
+                if (channel === undefined) channel = 0;
             } else {
                 // No instrument configured: silent — no FluidSynth, no oscillator.
                 return;
             }
-            if (ch === undefined) ch = (usedBank === 128 ? 9 : 0);
+            if (channel === undefined) channel = (usedBank === 128 ? 9 : 0);
+            var ch = channel;
             var ctx = getCtx();
             var now = ctx.currentTime;
             var delay = (typeof startTime === 'number' && startTime > now) ? (startTime - now) : 0;
@@ -405,6 +393,23 @@
             var self = this;
             var doNote = function () {
                 try {
+                    // Program change at note time, not call time — ensures correct
+                    // instrument for each item regardless of processing order.
+                    if (synthEngine) {
+                        var sfHandle = synthEngine.soundfont_id ? _sfHandleMap.get(synthEngine.soundfont_id) : undefined;
+                        if (sfHandle !== undefined) {
+                            try {
+                                _fluidModule._fluid_synth_program_select(_synthPtr, ch, sfHandle, usedBank, usedProg);
+                            } catch (e) {}
+                        } else {
+                            try { _fluidModule._fluid_synth_bank_select(_synthPtr, ch, usedBank); } catch (e) {}
+                            try { _fluidModule._fluid_synth_program_change(_synthPtr, ch, usedProg); } catch (e) {}
+                        }
+                    } else if (program !== undefined) {
+                        try {
+                            _fluidModule._fluid_synth_program_change(_synthPtr, ch, usedProg);
+                        } catch (e) {}
+                    }
                     console.log("[SonicSF] noteOn ch:", ch, "pitch:", midiPitch, "vel:", midiVel);
                     _fluidModule._fluid_synth_noteon(_synthPtr, ch, midiPitch, midiVel);
                     var noteMapKey = (_origChannel !== undefined ? _origChannel : 0) + ':' + midiPitch;
diff --git a/wiki.md b/wiki.md
index 599c741..50ba5c1 100644
--- a/wiki.md
+++ b/wiki.md
@@ -539,6 +539,12 @@
 - **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 09:50] Task: Program change ở note time, không phải call time
+- **Tóm tắt thay đổi:** Di chuyển `program_change`/`program_select`/`bank_select` từ synchronous (call time) vào trong `doNote` (note time via setTimeout) trong `_playNoteFluid`. Trước đây tất cả program_changes xảy ra ngay khi `startTrackPlayback` chạy → MIDI items processed trước sections → section's program_change override cuối cùng → ALL notes (section + MIDI) play với section instrument. Fix: mỗi note có program_change tại đúng thời điểm của nó.
+- **Các file ảnh hưởng:** `app/static/js/services/soundfontPlayer.js`
+- **Ghi chú/Test (nếu có):** load. TRACK 1: | SECTION ITEM (inst B) | MIDI ITEM (inst A) | → section plays inst B, MIDI item plays inst A.
+---
+
 ### [2026-07-28 09:30] Task: Thêm _isSectionClone flag — tắt âm thanh mặc định trong SECTION-TAB
 - **Tóm tắt thay đổi:** Thêm `_isSectionClone: true` vào section cloned tracks. Line 10283 kiểm tra flag: nếu section clone và không instrument → `undefined` (silent); nếu MAIN track và không instrument → `0` (GM Piano). Trước đây section cloned tracks đi qua line 10283 với `instrumentProgram: undefined` → default 0 → play GM Piano.
 - **Các file ảnh hưởng:** `app/static/js/app.jsx`, `app/static/js/app.precompiled.js`