diff --git a/frontend/src/melodies/PlaybackModal.jsx b/frontend/src/melodies/PlaybackModal.jsx
index 10244d6..f506d9c 100644
--- a/frontend/src/melodies/PlaybackModal.jsx
+++ b/frontend/src/melodies/PlaybackModal.jsx
@@ -357,9 +357,9 @@ export default function PlaybackModal({ open, melody, builtMelody, files, archet
                   <p className="text-xs mb-2" style={mutedStyle}>Note → Assigned Bell</p>
                   <div className="flex flex-wrap gap-1.5">
                     {noteAssignments.map((assignedBell, noteIdx) => {
-                      // A note is active if the current step has this note's bit set (raw archetype value)
-                      const isActive = currentStep >= 0 && Boolean(steps[currentStep] & (1 << noteIdx));
+                      // A note is active (flashing) if its assigned bell is currently lit in activeBells
                       const firesABell = assignedBell && assignedBell > 0;
+                      const isActive = firesABell && activeBells.has(assignedBell);
                       return (
                         <div
                           key={noteIdx}
diff --git a/frontend/src/melodies/SpeedCalculatorModal.jsx b/frontend/src/melodies/SpeedCalculatorModal.jsx
index 06f66fd..24295a7 100644
--- a/frontend/src/melodies/SpeedCalculatorModal.jsx
+++ b/frontend/src/melodies/SpeedCalculatorModal.jsx
@@ -127,6 +127,7 @@ export default function SpeedCalculatorModal({ open, melody, builtMelody, archet
   // Playback
   const audioCtxRef = useRef(null);
   const playbackRef = useRef(null); // { timer, stepIndex }
+  const flashTimerRef = useRef(null);
   const stepsRef = useRef([]);
   const stepDelayRef = useRef(500);
   const effectiveBeatRef = useRef(100);
@@ -136,6 +137,7 @@ export default function SpeedCalculatorModal({ open, melody, builtMelody, archet
   const [paused, setPaused] = useState(false);
   const [loop, setLoop] = useState(true);
   const [currentStep, setCurrentStep] = useState(-1);
+  const [activeBells, setActiveBells] = useState(new Set());
 
   // Sliders
   const [stepDelay, setStepDelay] = useState(500);
@@ -175,6 +177,7 @@ export default function SpeedCalculatorModal({ open, melody, builtMelody, archet
       setCapturedNormal(normal);
       setBinaryLoadError("");
       setCurrentStep(-1);
+      setActiveBells(new Set());
       setPlaying(false);
       setPaused(false);
       setSaveError("");
@@ -198,9 +201,14 @@ export default function SpeedCalculatorModal({ open, melody, builtMelody, archet
       clearTimeout(playbackRef.current.timer);
       playbackRef.current = null;
     }
+    if (flashTimerRef.current) {
+      clearTimeout(flashTimerRef.current);
+      flashTimerRef.current = null;
+    }
     setPlaying(false);
     setPaused(false);
     setCurrentStep(-1);
+    setActiveBells(new Set());
   }, []);
 
   useEffect(() => {
@@ -237,6 +245,17 @@ export default function SpeedCalculatorModal({ open, melody, builtMelody, archet
     const stepValue = currentSteps[playFrom];
 
     setCurrentStep(playFrom);
+
+    // Flash active bells for tone length, then clear
+    const bellsNow = new Set();
+    getActiveBells(stepValue).forEach((b) => bellsNow.add(b));
+    setActiveBells(bellsNow);
+    if (flashTimerRef.current) clearTimeout(flashTimerRef.current);
+    flashTimerRef.current = setTimeout(() => {
+      setActiveBells(new Set());
+      flashTimerRef.current = null;
+    }, effectiveBeatRef.current);
+
     playStep(ctx, stepValue, effectiveBeatRef.current);
 
     const delay = stepDelayRef.current;
@@ -353,7 +372,6 @@ export default function SpeedCalculatorModal({ open, melody, builtMelody, archet
     getActiveBells(v).forEach((b) => set.add(b));
     return set;
   }, new Set());
-  const currentBells = currentStep >= 0 ? getActiveBells(steps[currentStep] || 0) : [];
   const maxBell = allBellsUsed.size > 0 ? Math.max(...Array.from(allBellsUsed)) : 0;
 
   return (
@@ -439,12 +457,12 @@ export default function SpeedCalculatorModal({ open, melody, builtMelody, archet
               {totalSteps > 0 && (
                 <div>
                   <p className="text-xs mb-2" style={mutedStyle}>
-                    Bell indicator
+                    Notes Indicators
                     {currentStep >= 0 && <span> &nbsp;·&nbsp; Step {currentStep + 1} / {totalSteps}</span>}
                   </p>
                   <div className="flex flex-wrap gap-1.5">
                     {Array.from({ length: maxBell }, (_, i) => i + 1).map((b) => {
-                      const isActive = currentBells.includes(b);
+                      const isActive = activeBells.has(b);
                       const isUsed = allBellsUsed.has(b);
                       return (
                         <div