diff --git a/app/static/js/app.jsx b/app/static/js/app.jsx
index a2056ed..614d63d 100644
--- a/app/static/js/app.jsx
+++ b/app/static/js/app.jsx
@@ -9198,8 +9198,7 @@ const App = () => {
   const [saveProjectModalOpen, setSaveProjectModalOpen] = useState(false);
   const [saveAsModalOpen, setSaveAsModalOpen] = useState(false);
   const [openProjectModalOpen, setOpenProjectModalOpen] = useState(false);
-  const soloedTrack = tracks.find(t => t.solo);
-  const soloedTrackId = soloedTrack ? soloedTrack.id : null;
+  const hasAnySolo = tracks.some(t => t.solo);
   const [toastMessage, setToastMessage] = useState(null);
   const [audioDevices, setAudioDevices] = useState([]);
   const [midiDevices, setMidiDevices] = useState([]);
@@ -12985,12 +12984,16 @@ const App = () => {
     // If selection cleared by user, play linearly (don't loop)
     if (!selectionCleared && isLoopingSelection && selLeft !== null && selRight !== null) {
       if (selRight > selLeft && updatedTime >= selRight) {
-        if (soloedTrackId !== null || selectionMode === 'local') {
+        if (hasAnySolo || selectionMode === 'local') {
           stopAllPlayback();
           startOffsetTimeRef.current = selLeft;
           startAudioTimeRef.current = context.currentTime;
-          const soloTid = soloedTrackId !== null ? soloedTrackId : localSelectionTrackId;
-          startLocalTrackPlayback(soloTid, selLeft);
+          if (hasAnySolo) {
+            const soloed = tracks.filter(t => t.solo);
+            soloed.forEach(t => startLocalTrackPlayback(t.id, selLeft));
+          } else {
+            startLocalTrackPlayback(localSelectionTrackId, selLeft);
+          }
           setCurrentTime(selLeft);
           setIsPlaying(true);
         } else {
@@ -13164,9 +13167,9 @@ const App = () => {
 
   const startTrackPlayback = offsetTime => {
     const context = getAudioContext();
-    const hasSolo = activeTracks.some(t => t.solo) || soloedTrackId !== null;
+    const hasSolo = activeTracks.some(t => t.solo);
     activeTracks.forEach(track => {
-      const isPlayable = hasSolo ? track.id === soloedTrackId || track.solo : !track.muted;
+      const isPlayable = hasSolo ? track.solo : !track.muted;
       if (!isPlayable) return;
 
       const gainNode = getOrCreateTrackNode(track, context);
@@ -20022,8 +20025,8 @@ const App = () => {
           toggleTrackSoloEvaluate(track.id);
         },
         title: "Solo",
-        className: `px-1.5 py-0.5 text-[10px] rounded font-mono font-bold border transition flex items-center gap-0.5 ${soloedTrackId === track.id || track.solo ? 'bg-amber-950 text-amber-400 border-amber-600' : 'bg-zinc-800 text-zinc-400 border-transparent hover:text-zinc-200'}`
-      }, /*#__PURE__*/React.createElement("i", { "data-lucide": soloedTrackId === track.id || track.solo ? "headphones" : "headphone-off", className: "w-3 h-3" })), /*#__PURE__*/React.createElement("button", {
+        className: `px-1.5 py-0.5 text-[10px] rounded font-mono font-bold border transition flex items-center gap-0.5 ${track.solo ? 'bg-amber-950 text-amber-400 border-amber-600' : 'bg-zinc-800 text-zinc-400 border-transparent hover:text-zinc-200'}`
+      }, /*#__PURE__*/React.createElement("i", { "data-lucide": track.solo ? "headphones" : "headphone-off", className: "w-3 h-3" })), /*#__PURE__*/React.createElement("button", {
         onClick: e => {
           e.stopPropagation();
           toggleTrackDrum(track.id);
@@ -20548,7 +20551,7 @@ const App = () => {
           e.stopPropagation();
           toggleTrackSoloEvaluate(vTrack.id);
         },
-        className: `px-1.5 py-0.5 text-xs rounded font-mono font-bold border ${soloedTrackId === vTrack.id || vTrack.solo ? 'bg-amber-950 text-amber-400 border-amber-600' : 'bg-zinc-800 text-zinc-400 border-transparent hover:text-zinc-200'}`
+        className: `px-1.5 py-0.5 text-xs rounded font-mono font-bold border ${vTrack.solo ? 'bg-amber-950 text-amber-400 border-amber-600' : 'bg-zinc-800 text-zinc-400 border-transparent hover:text-zinc-200'}`
       }, "S"))), /*#__PURE__*/React.createElement("div", {
         className: "flex flex-col gap-2.5 text-[14px] mb-3"
       }, /*#__PURE__*/React.createElement("div", {
@@ -20992,9 +20995,9 @@ const App = () => {
     className: "text-amber-400 font-semibold uppercase text-xs"
   }, "Local Sel"), selectionMode === 'global' && /*#__PURE__*/React.createElement("span", {
     className: "text-purple-400 font-semibold uppercase text-xs"
-  }, "Global Sel"), soloedTrackId && /*#__PURE__*/React.createElement("span", {
+  }, "Global Sel"), hasAnySolo && /*#__PURE__*/React.createElement("span", {
     className: "text-amber-500 font-semibold"
-  }, "Solo: ID ", soloedTrackId), isLoopingSelection && selectionMode === 'local' && /*#__PURE__*/React.createElement("span", {
+  }, "Solo: ", tracks.filter(t => t.solo).length, " track(s)"), isLoopingSelection && selectionMode === 'local' && /*#__PURE__*/React.createElement("span", {
     className: "text-emerald-400 font-semibold uppercase text-xs"
   }, "Solo Loop"), isLoopingSelection && selectionMode !== 'local' && /*#__PURE__*/React.createElement("span", {
     className: "text-cyan-400 font-semibold uppercase text-xs"
diff --git a/wiki.md b/wiki.md
index 21484dd..a1a07c3 100644
--- a/wiki.md
+++ b/wiki.md
@@ -4,6 +4,12 @@
 - **Ghi chú/Test (nếu có):** Không cần build. Fix áp dụng cho tất cả đường dẫn tạo track: addNewTrack, insertTrackBelow, AI cut/composition/rearrange, MIDI import, section clone.
 ---
 
+### [2026-07-31 07:09] Task: Allow multiple simultaneous solo buttons (Track TCP)
+- **Tóm tắt thay đổi:** `toggleTrackSoloEvaluate` trước đây set `solo: false` cho tất cả track trừ track được click → chỉ cho phép 1 solo. Fix: toggle solo chỉ trên track được click, giữ nguyên trạng thái solo của track khác. `soloedTrackId` (single track ID) được thay bằng `hasAnySolo` (boolean). `startTrackPlayback` dùng `track.solo` trực tiếp thay vì so sánh với `soloedTrackId`. Loop restart với solo: iterate tất cả soloed tracks thay vì chỉ play 1 track. UI highlight các nút solo dùng `track.solo`.
+- **Các file ảnh hưởng:** `app/static/js/app.jsx`
+- **Ghi chú/Test (nếu có):** Bấm solo track A → active, bấm solo track B → cả A và B đều solo. Audio playback chỉ play track có solo = true.
+---
+
 ### [2026-07-28 07:56] Task: Fix PIANO_ROLL activeTracks + instrument auto-assign trong SECTION-TAB
 - **Tóm tắt thay đổi:** Fix `activeTracks` useMemo: khi `activeTab` là PIANO_ROLL sub-tab từ SECTION-TAB (`parent_tab_id` bắt đầu `session_`), trả về tracks của section tab thay vì main tracks. Trước đây `activeTracks` luôn trả về main tracks khi activeTab !== session_xxx → dropdown MIDI item rỗng, track name không hiển thị, instrument lookup sai. Fix: check `subTabs` cho PIANO_ROLL type để resolve đúng parent session tracks.
 - **Các file ảnh hưởng:** `app/static/js/app.jsx`, `app/static/js/app.precompiled.js`