diff --git a/app/static/js/services/soundfontPlayer.js b/app/static/js/services/soundfontPlayer.js
index d976037..3dbea9b 100644
--- a/app/static/js/services/soundfontPlayer.js
+++ b/app/static/js/services/soundfontPlayer.js
@@ -321,9 +321,15 @@
             if (channel < 0 || channel > 15) return;
             if (_initialized && _fluidModule) {
                 var key = channel + ':' + pitch;
-                var mappedCh = _activeNotes[key];
-                console.log("[SonicSF] stopNote ch:", channel, "pitch:", pitch, "key:", key, "mappedCh:", mappedCh, "activeKeys:", Object.keys(_activeNotes));
-                if (mappedCh === undefined) mappedCh = channel;
+                var mappedChs = _activeNotes[key];
+                if (mappedChs === undefined) {
+                    if (_activeNotes['_' + key]) mappedChs = _activeNotes['_' + key];
+                }
+                if (mappedChs === undefined) mappedChs = [channel];
+                if (!Array.isArray(mappedChs)) mappedChs = [mappedChs];
+                for (var i = 0; i < mappedChs.length; i++) {
+                    try { _fluidModule._fluid_synth_noteoff(_synthPtr, mappedChs[i], pitch); } catch (e) {}
+                }
                 delete _activeNotes[key];
                 try {
                     var r1 = _fluidModule._fluid_synth_noteoff(_synthPtr, mappedCh, pitch);
@@ -397,13 +403,19 @@
                 try {
                     console.log("[SonicSF] noteOn ch:", ch, "pitch:", midiPitch, "vel:", midiVel);
                     _fluidModule._fluid_synth_noteon(_synthPtr, ch, midiPitch, midiVel);
-                    _activeNotes[(_origChannel !== undefined ? _origChannel : 0) + ':' + midiPitch] = ch;
                     var noteMapKey = (_origChannel !== undefined ? _origChannel : 0) + ':' + midiPitch;
+                    if (!_activeNotes[noteMapKey]) _activeNotes[noteMapKey] = [];
+                    if (_activeNotes[noteMapKey].indexOf(ch) === -1) _activeNotes[noteMapKey].push(ch);
                     if (durationMs > 0 && durationMs < 60000) {
                         scheduledNote.off = setTimeout(function () {
                             try {
                                 _fluidModule._fluid_synth_noteoff(_synthPtr, ch, midiPitch);
-                                delete _activeNotes[(_origChannel !== undefined ? _origChannel : 0) + ':' + midiPitch];
+                                var arr = _activeNotes[noteMapKey];
+                                if (arr) {
+                                    var idx = arr.indexOf(ch);
+                                    if (idx >= 0) arr.splice(idx, 1);
+                                    if (arr.length === 0) delete _activeNotes[noteMapKey];
+                                }
                             } catch (e) {}
                         }, durSec * 1000);
                     }