Piano synth · qwen3.8-max-0902

I'll start by checking what's in the current directory.

Let me build index.html.

Notes: C4, C#4, D4, D#4, E4, F4, F#4, G4, G#4, A4, A#4, B4, C5. Keys: A W S E D F T G Y H U J K.

Use Tone.PolySynth with Tone.Synth (ADSR envelope). Handle pointerdown/pointerup/pointerleave, keydown repeat guard, blur.

Also need to release voices when pointer released outside a key — use window pointerup handler.

Let me write it.

Note: I used `el.style.order` for white keys but black keys are absolutely positioned — order doesn't matter for absolute ones, but flex order applies to white keys only among flex items. Since black keys are absolute (out of flow), white keys flow in DOM order anyway which is already correct. Order is redundant but harmless. Actually with `order` set only on white keys, default order 0 for absolute ones (not laid out in flex). Fine.

Left position: white key i occupies left = PAD + i*67 (since margin-right 3). The black key between white i and i+1 should be centered at PAD + (i+1)*67 - 1.5. My left = PAD + whiteIndex*67 - 20 - 1.5 where whiteIndex is the index of the next white key (since incremented after previous white appended). Wait — for C#4, previous white was C4 with whiteIndex 0 → then whiteIndex becomes 1. Black left = 10 + 1*67 - 21.5 = 55.5. C4 spans 10..74 (width 64), D4 spans 77..141. Boundary is 74..77, center 75.5. Black key centered: 55.5+20 = 75.5. ✓

Let's test in browser.

The layout looks correct: white keys C4, D4, E4, F4, G4, A4, B4, C5, and black keys C#4, D#4, F#4, G#4, A#4 are placed at the correct boundaries. Labels are displayed.

Console: The worker CSP error from Tone.js (blob worker) — this is Tone.js internal processing and is blocked by CSP, but it's a warning/error that Tone emits at load time. It says "Creating a worker from blob violates CSP worker-src 'none'". This happens at load time. Is this fatal? Tone.js falls back. This error appears in the console. It's from the library itself, unavoidable unless patched. Hmm, "check the console after audio activation" — the worker error occurs at load time, not after activation. It might be tolerable, but it would be better if we could avoid it. Tone.js uses a worker for... I recall Tone.js v14 was using a blob worker for the "Tone.js worker"? Actually, does Tone use a worker in `Tone/core/context/...`? I think it's for offline rendering or the "Draw" scheduling? Let me check: does tone.min.js contain `new Worker` for the "clock"? Actually, I recall Tone.js was using a blob worker in `Tone/core/util/Worker` for deferred execution of `dispose`/cleanup. There's a fallback when worker creation fails. The error message is logged by the browser (CSP violation), not by Tone. It can't be fully avoided unless we patch the library. The task says to check the console after audio activation — the AudioContext warning before a gesture is expected, and should disappear after a gesture (Tone.start resumes it). The worker CSP error at load time is a library side-effect in the sandboxed iframe. Probably tolerable, but let's see if there's a way: maybe setting `Tone.config.lookAhead = 0`? The worker is used in `Tone/core/util/Draw`? Hmm.

Actually, in Tone.js v14.8.x, the blob worker is created in `Tone/core/context/OfflineContext`? No... let me grep tone.min.js for "Worker".

Also, the AudioContext warning appears because Tone creates the context at load time. Unavoidable.

Let me test the interaction: click a key, verify highlighting and audio state; press a keyboard key; check the console after activation.

Audio is active after the click. The click was a quick down+up, so the note was released. The screenshot doesn't show the active state (already released).

Next, test the press-and-hold highlight: use drag? The browser tool has click (down+up), key (key press?), and motion. To observe the highlight during hold, I can dispatch pointerdown via evaluate... but there's no evaluate tool. I can use the "key" action for keydown/keyup. The key action probably sends a key press (down+up?). Let me check what the key action does — probably presses and releases. The highlight during hold might be captured with a motion frame?

Alternative: use the debug hook window.__piano? Can't evaluate JS directly... The browser tool only has the listed actions. Hmm, "inspect" returns DOM/console. There's no evaluate.

To verify the highlight during hold, I can use drag: pointerdown at one point, move to another, release. During drag, the pointer is held down. The motion action captures frames over time. Let me try dragging from the C4 key to somewhere and capturing a frame mid-hold.

Actually, drag: from (368,350) to (368,350)? Same coordinates might not generate a move. Drag to a different point on the same key: (368,300) → (368,320). During that, pointerdown fires and the note turns on; pointerup at the end releases it. The motion frame might capture the active class.

Also test keyboard: key action with text? The key action's parameters: probably x,y? No — key probably takes `text` as the key name. Let me try key with text "a".

First, do a drag to capture the hold highlight.

The drag ended before the screenshot (the final frame shows the released state). The screenshot was taken after the drag completed, so the highlight isn't visible. Need to capture during the hold. The "motion" action captures frames over time — maybe I can start a drag and then take motion frames? But the tool calls are sequential, and the drag completes before motion starts.

Alternative: verify the highlight via keyboard: the "key" action probably presses and releases quickly too.

Better approach: verify the highlight state via the DOM. Use inspect after dispatching? Can't hold state between calls... unless I trigger noteOn via the debug hook — but there's no evaluate action.

Hmm, but the browser tool's "motion" action: "view screenshots or motion frames" — motion probably records frames over a certain period. If keyboard keydown is held down... the key action probably does down+up.

Options: test the highlight logic indirectly. The active class is toggled in paint() on noteOn/noteOff. The drag screenshot shows the final released state, which is consistent with release working. To capture the pressed state, maybe I can use a drag that ends outside the window? No, that won't work.

Maybe the motion action takes screenshots during an operation? Unclear. Let me try: does the key action hold? Let me try the key action with text "a" and see if the screenshot shows the highlight (probably taken after keyup).

Alternative approach: add a small self-test? No — better: use the "motion" action right after dispatching pointerdown... but I can't dispatch without evaluate.

Wait — maybe the drag action captures motion frames during the drag? The result said "Frame 1, +0ms" and an image was attached — that's the final frame. The motion action might record frames over a certain period. If I start a drag that lasts longer... the drag completes immediately.

Hmm, what about pointer capture: my pointerdown handler calls board.setPointerCapture. During the drag, the note turns on; on pointerup it turns off. The screenshot after the drag shows the off state — correct behavior.

To visually verify the highlight, maybe I can slow things down: use motion with a drag? The motion action's signature has no operation parameters.

Alternative: temporarily verify with a long attack? No, the highlight is class-based.

Maybe I can check the DOM during the hold: use the "key" action which might support holding? The parameters include text. Probably it sends keydown+keyup.

Realistic approach: trust the class toggle (simple), but verify with a temporary modification: add a query parameter or debug: e.g., a "sticky test" mode? That would pollute the artifact.

Better: use the browser's motion action after triggering a long-held note via keyboard auto-repeat? No, that won't work.

Hmm — maybe the "key" action only sends keydown (press), and a separate keyup? Let me try: run the key action with text "a", then immediately inspect the DOM (separate call). If key sends down+up together, the state will be released. If it only sends down, the highlight will remain and I can verify with inspect, then send keyup afterward.

Let me try: browser key with text "a", then inspect.

The key action performs both press and release (the screenshot after release shows no highlight, and there's no stuck note either). The console after audio activation shows no new errors — only the initial load-time warnings (worker CSP from the Tone.js blob worker, and the autoplay warning from before the gesture). These occurred before the gesture, and no errors have occurred after activation.

The worker CSP error at load time: Tone.js creates a blob Worker at import time. In the sandboxed runner it gets blocked and logs an error. Tone falls back gracefully (it's used for deferred cleanup). Can we avoid it? Options: patch after load? The error occurs when Tone is loaded (script execution). We can't intercept it before the library runs, unless we set something up first. Actually, where in Tone is the worker created? Let's grep tone.min.js for "Worker(".

If it's lazily created (e.g., on first dispose), the error at load time suggests eager creation. Let me check.

There's only one usage of `new Worker(e)`. Let me look for the context around it.

The worker is for Tone's Clock (lookahead scheduler). `_createClock` tries the worker, catches the exception, and falls back to timeout. However, the CSP violation error is still logged to the console by the browser (the blocked action). This is a browser-level log, and since Tone creates the worker at context creation time (at load time), it cannot be caught by page code.

Can we prevent this? The Clock's type is determined by `this._type`, which defaults to "worker". If we can set it before context creation... The Clock instance is created when the Tone context is created (at load time, when the module is initialized? Actually, the context is lazily created on first use, but the warning indicated that the AudioContext was created at load time). The worker error appeared at load time (before any gesture). Hmm, actually it appeared in the console on the first load—right, at load time.

Options: define a global shim before loading tone.min.js: override `window.Worker` with a wrapper that throws? If `new Worker(e)` throws synchronously, Tone catches it and falls back to timeout—but the browser's CSP error log happens when the actual Worker constructor is invoked. If we replace window.Worker with our own class that doesn't create a real worker (e.g., a fake that mimics the timeout behavior), no CSP error will be logged. But faking the worker's tick behavior: the worker script posts 'tick' messages at intervals. We can implement a fake Worker that runs the same logic on the main thread: but the blob URL's contents are the worker source; simpler: implement a FakeWorker class whose postMessage/onmessage mimic: Tone's clock worker: onmessage receives {data: timeoutTime}; posts 'tick' at setTimeout intervals. Tone sets s.onmessage = callback; and probably posts messages to set the interval. We can implement:

class FakeWorker {
  constructor(){ this._timeout=null; this.onmessage=null; this._run(); }
  _run(){ this._timeout=setTimeout(()=>{ this._run(); if(this.onmessage) this.onmessage({data:'tick'}); }, this._interval|| (0.03*1000)? }
Hmm, the default timeoutTime inside the worker: `timeoutTime` is initialized to... the snippet shows `self.onmessage = function(msg){ timeoutTime = parseInt(msg.data); }` and tick schedules setTimeout(tick, timeoutTime). The initial timeoutTime is probably defined above the snippet. Tone posts the update interval to the worker.

Simpler and safer approach: wrap the native Worker: override window.Worker with a subclass that tries native in try/catch? The CSP error is logged by the browser regardless of catch. So to avoid the console error, we must not call the native Worker at all.

Implementing a fake worker:

(function(){
  var NativeWorker = window.Worker;
  function FakeWorker(url){
    var self = this;
    this.onmessage = null;
    var timeoutTime = 30; // ms? worker default
    ...
  }
})

But what does Tone post to the worker? Let's look for postMessage calls to _worker. Grep for "_worker.postMessage".

In other words, the worker's source embeds the initial timeoutTime = 1000*_updateInterval (default updateInterval = 0.03 → 30ms? Actually, is Tone's default lookAhead update interval 0.03 seconds? Is the Clock's default `_updateInterval` 0.03?). The worker ticks by postMessage('tick') every timeoutTime ms, and onmessage updates timeoutTime from the posted data.

Where does Tone post updates? Search for "postMessage" within tone.min.js.

The clock posts `1e3*this._updateInterval` to the worker on updates, and probably posts 0 to pause? "postMessage(0)" appears twice — likely to stop the tick (timeoutTime=0 → setTimeout(tick,0)? Hmm, that would spin). Actually, in Tone's Clock worker source, tick uses setTimeout(tick, timeoutTime); when timeoutTime is 0 it spins fast — used during playback? Not sure. And "dispose" terminates it.

Implementing a faithful fake worker:

function FakeWorker(url){
  var self=this; this.onmessage=null; this._t=null;
  var timeoutTime = 30; // will be set immediately by Tone's postMessage(1e3*updateInterval)
  function tick(){ self._t=setTimeout(function(){ tick(); if(self.onmessage) self.onmessage({data:'tick'}); }, timeoutTime); }
  this.postMessage=function(d){ timeoutTime=parseInt(d); if(self._t){clearTimeout(self._t); self._t=null;} if(timeoutTime>0){ tick(); } };
  this.terminate=function(){ if(self._t) clearTimeout(self._t); };
}

Wait, but the worker's own tick(): first schedules the next, then posts. When a new timeoutTime is posted, the worker just changes the variable; the pending timeout still uses the old value at schedule time... In the actual worker, tick(){ setTimeout(tick, timeoutTime); postMessage('tick'); } — the next delay reads the current timeoutTime at the time of the call. My fake: on postMessage(d): timeoutTime=parseInt(d); clear pending; if >0 restart tick loop. Behavior: ticks every timeoutTime ms. When 0 is posted: real worker: timeoutTime=0 → next setTimeout(tick,0) spins posting ticks as fast as possible. Hmm, when is 0 posted? Probably when the context is suspended/disposed to stop the clock? Spinning at 0 seems wrong... Actually, in the real worker, postMessage(0) → timeoutTime=0; the currently pending timeout fires later, then schedules setTimeout(tick,0) → fast spin. That can't be the intent. Maybe postMessage(0) is for a different worker (audio decode?). There are multiple postMessage calls for other purposes (MessageChannel etc.).

Where is postMessage(1e3*this._updateInterval)? Inside Clock's _updateInterval setter. And postMessage(0)? Let me check the context.

Risk assessment: is it worth shimming Worker? The console error appears once at load. The task says "check the console after audio activation" — the worker error occurs at load, before activation, and doesn't recur. It's a sandbox CSP artifact from the library itself, and Tone handles it gracefully (falls back to the timeout clock). Shimming Worker risks breaking Tone's clock if my fake misbehaves (e.g., transport scheduling). The timeout fallback is Tone's own supported path ("timeout" type). If my fake worker replaces the native one, Tone will think it has a worker clock but receive ticks from my main-thread loop — functionally equivalent to the timeout clock.

Safer alternative shim: make `new Worker()` throw immediately so Tone's own catch falls back to its own timeout clock:

window.Worker = function(){ throw new Error("worker disabled"); };

But Tone calls `new Worker(e)` inside try{this._createWorker()}catch(t){this._type="timeout";this._createClock()}. If my shim throws, Tone falls back to its built-in timeout clock — fully supported, no CSP error in console (my throw is caught; though I might want to avoid logging). But wait: is `new Worker(e)` the only worker creation? Also, does anything else use Worker (e.g., Compressor? No). grep shows only one "new Worker". Also `URL.createObjectURL` is fine.

But note: replacing window.Worker globally might affect other code — only Tone uses it here.

However: does the CSP error also occur from `URL.createObjectURL`? No, only worker-src.

Also, the initial console showed the worker error at load time — meaning the Clock was created at load time (Tone's default context + clock are created immediately). With the shim throwing, Tone falls back to the timeout clock: `_createTimeout` sets a 1-second interval? Wait: `_createTimeout(){this._timeout=setTimeout((()=>{this._createTimeout(),this._callback()}),1e3*this._updateInterval)}` — same tick behavior as the worker but on the main thread.

Hmm, but where is _type set? `this._type` defaults to "worker"? And _createClock: if type==="worker" try worker catch → type="timeout", _createClock() again → timeout branch. Good.

Edge case: my shim must be a constructor usable with `new`. `window.Worker = function(){throw ...}` works with new (the throw propagates).

But also, does anything check `typeof Worker !== "undefined"` or use worker features elsewhere (e.g., Tone's OfflineContext uses worker? No). Only one occurrence.

Also, the browser logs the CSP error itself when the native constructor is called; with the shim, the native is never called.

Is suppressing this "cheating"? It's a graceful degradation to the library's own fallback, and keeps the console clean in the sandboxed artifact. I think it's justified: the artifact runs fully sandboxed with worker-src 'none'; the library's worker is impossible; the shim routes to the supported fallback without a scary console error.

Implement before the tone.min.js script tag:

<script>
// The sandbox forbids blob workers (CSP worker-src 'none'); Tone.js falls back
// to its main-thread timeout clock when Worker construction throws.
(function(){
  function BlockedWorker(){ throw new Error("Workers are disabled in this sandbox; using timeout clock."); }
  try { window.Worker = BlockedWorker; } catch(e){}
})();
</script>

Wait, but if some environment needs a real worker... not here.

Hmm, but also consider: Tone might only create the clock lazily on context creation; either way it's fine.

Also, the AudioContext autoplay warning at load: Tone creates the context at load. Can we defer it? The warning "The AudioContext was not allowed to start" appears because the context is created before a gesture. Tone v14 creates the default context on module init. Can we avoid it? There's `Tone.deferred`? Not really. The warning disappears after resume (state running). It's a warning, not an error; acceptable. But could we reduce it by creating the context only on gesture? Tone's module init instantiates `new Context()`? The default context is lazy: `getContext()` creates on first use... but the warning appeared at load, so something used it at load (probably the Clock/Draw startup or Transport). Hmm, the warning appeared twice at load.

Maybe set `Tone.context` later? Not easy to prevent module side effects. Accept the warning: it's standard for any WebAudio app before a gesture, and after a user gesture the state becomes running and no further warnings appear.

Now, also double-check that "postMessage(0)" isn't needed for the timeout clock — irrelevant since we're using Tone's own fallback.

Apply the shim edit, reload, and confirm the console is clean except for the autoplay warning (which should clear after a gesture... the warning line remains in console history but no new ones).

Then continue verification: highlight during hold. Idea: use the motion action? Let's see what motion does: "motion frames" — probably captures frames over time without interaction. Not useful for holding.

To visually verify the pressed highlight, we can rely on: drag captures the final frame after release. Hmm, but maybe the drag action returns multiple frames? It said "Frame 1, +0ms" with a single image. The motion action might take parameters? Only action + coordinates.

Alternative: verify the highlight via DOM inspection during hold: can we hold via OS? Not available.

Trick: the key action might support holding via text like "a down"? Unknown. Let's test: send key "a" then immediately inspect — the earlier key result already included the post-release DOM (no active). If key were holding, we'd have seen active. So key = down+up.

What about `type` action? Types text — probably also generates keydown/keyup per character.

Hmm, drag: pointerdown at start, move, pointerup at end — all within one action; the screenshot is after. So we can't catch mid-hold via these.

Options: temporarily add a test hook: e.g., hold on shift+click? No.

We can verify the highlight logic via code review (class toggling in paint()) plus evidence that noteOn/noteOff fire (chips also toggle). For observable evidence, add a visible "last event" readout? E.g., status shows "note on: C4 / off". Then after a quick click, status shows the last off; still not mid-hold.

Better: use motion action during drag? Can't run concurrently.

Alternative: make hold observable post-hoc: add a "currently held notes" readout that lists held notes; after release it's empty — proves the release happened; but the hold happened in between. To prove the highlight was displayed during hold, we can record peak: e.g., a counter "notes started / released" and a "held now" list. If held-now is empty after release and the started counter incremented, plus the code toggles the class on on/off, that's reasonable.

Even better: capture mid-hold via pointer capture trick: pointerdown on a key, then pointerup outside the window — the browser tool can't release outside the window.

Hmm, actually maybe we can catch mid-hold: the `drag` tool might insert a delay between move and up? Unknown.

What about CSS transitions: the active class has a 0.07s background transition; after release the class is removed immediately. No.

Use scroll? No.

OK, another approach: keyboard event with repeat: send key "a" multiple times? Still down+up pairs.

I think acceptable verification is: (1) code review of the handlers (task explicitly says "briefly inspect input handlers for matching note-start and note-release behavior" — code review is expected), (2) observable: add a debug readout showing held notes live; then use drag and... still post-hoc.

Hmm wait — maybe the motion action: "Run index.html ... see screenshots or motion frames." Maybe motion records a few frames over ~1-2s. If we could start a sustained note before calling motion... e.g., call `type`? No.

What about a pointerdown that never receives pointerup: drag from key A to key A (same coords)? If toX==toY==start, maybe the tool does down, move(0), up. Still up.

Use click at a coordinate, and the tool's click = down+up. Hmm.

Idea: exploit my own glissando logic? No.

Idea: use the debug hook via URL? Can't eval.

Honestly, simplest robust observable: make the highlight sticky-visible for verification? No, that breaks the spec (highlight while held).

Alternative: verify via console log: add console.log on noteOn/noteOff? Console spam but shows pairs. The task says check the console after audio activation — extra logs might be considered noise but demonstrate start/release pairs. Maybe better: update status text to "▶ C4 (held: 1)" on on and "released (held: 0)" on off. After a click, status shows the released state with counters: e.g., "started: 3, released: 3, held: 0". This proves matching pairs including via mouse and keyboard. And for mid-hold highlight, we can capture it via motion if we can hold...

Wait a moment — maybe we can hold: the `key` tool with text "a" sends keydown+keyup. But maybe there's a hold via repeated calls? No.

Let me look at the browser tool description again: "Run index.html, inspect DOM/console, interact, and see screenshots or motion frames." Actions: reload, inspect, screenshot, motion, click, drag, key, type, scroll. The motion action probably: captures N frames over a short window to show animation. If an animation is running... our highlight isn't an animation.

Decision: implement a status readout with counters + held list (good UX anyway: shows currently held notes). Then:
- Click a key → status shows release with counters 1/1.
- Press key 'w' → counters 2/2.
- Drag across keys → glissando counters.
And for visual mid-hold highlight: trust the CSS + class logic; plus we can do one more trick: pointerdown via drag that ends on the same key with pointer capture... still releases at the end.

Actually! There is a way: `drag` from a key to a point outside the board but inside the window: my window pointerup handler releases. Still ends.

Hmm, what about pointerleave during drag with buttons: my pointerleave releases. Ends.

OK — but wait: what about touch pointers? The drag tool probably uses mouse.

Alternatively, verify the highlight with a temporary test build: create a test copy of index.html with an auto-hold demo (e.g., ?hold=1 triggers noteOn without off after 500ms), screenshot that, then delete. The artifact stays clean; verification is real. The browser tool loads index.html — can it load test.html? "Run index.html" — probably fixed to index.html. Hmm, maybe serves the directory? Unknown; risky.

We can do this: temporarily modify index.html to add a hold demo (e.g., double-click = 2s hold), screenshot, then remove. Double-click as a hidden feature is harmless but adds code. Or keep a small feature: "Space = sustain demo chord"? Not in spec but harmless? Extra keys might confuse the mapping check.

Simplest: temporarily add `setTimeout(()=>{window.__piano.on("C4");},100); setTimeout(off, 2500)` guarded by location.hash === "#demo". Hash doesn't affect the artifact's normal use. Then reload with hash? The browser tool's reload probably reloads the same URL without hash. Can't control URL. Hmm.

Given the constraints, do this: temporary edit (add auto-hold on load behind a flag), screenshot to confirm highlight renders, then remove the flag and re-verify. This is a legitimate verification technique.

Actually cleaner: keep the debug hook window.__piano and add a temporary line calling it. Do:

Temporary: after init, `window.__piano.on("C4"); window.__piano.on("E4"); window.__piano.on("G4");` (3 simultaneous notes → also verifies polyphony ≥3 and multi-highlight). Screenshot. Then remove.

Let's first apply the Worker shim + status readout improvements, then do the temporary hold test.

Status readout: add a span #held showing held notes. Update in paint(): heldList = notes with held true; statusEl? Keep status for audio state; add a separate line under the board? Put it in the legend's controls row: "Held: —". Update in paint().

Also counters: started/released counts displayed small. Maybe overkill; the held list is enough plus code review.

Let's edit.

Wait: paint increments the counter on every call — noteOn calls paint(note,true) only when newly held (already guarded by held[note]); noteOff calls paint(note,false) only when held. Good.

But noteOff sets held[note]=false before paint → the list is computed correctly. noteOn sets held=true before paint. Good.

Next, reload and check the console (expecting no worker errors), then click and verify the counter.

The Worker CSP errors are gone. Only the expected autoplay warnings remain (before gesture). Next, play notes: click C4, then press a few keys, and check the counter. After that, do a temporary hold test for visual highlighting.

Sequence: click the C4 white key (368,350); press the keys "w", "e"? Then inspect.

Problem: After clicking C4, the counter shows "started 0 · released 0", and Held is also —. The click activated the audio, but the note didn't start?! Why?

Looking at noteOn: ensureAudio().then(...) — audioReady is set asynchronously. On the first click, ensureAudio returns a Promise; .then runs after Tone.start() resolves; audioReady is true; held is false → triggerAttack, paint. So the counter should increment... but the screenshot was taken right after the click; maybe the Promise resolved after the screenshot? Tone.start() resolves quickly, but the screenshot might be at the +0ms frame. However, the status shows "Audio active — state: running", which is set in the same .then before noteOn's .then? Order: ensureAudio's Promise chain: inside ensureAudio, .then sets audioReady and status. noteOn's .then is chained onto the Promise returned by ensureAudio (which returns the same chain? ensureAudio returns Tone.start().then(...)...). noteOn calls ensureAudio().then(cb) — cb runs after ensureAudio's internal then. Status update happened (visible), so cb should have run too... unless the screenshot/DOM snapshot was taken between them? Status shows active, counter shows 0 — but paint runs in noteOn's then, which is after ensureAudio's then (microtask order). Both are microtasks; DOM snapshot after both? The returned DOM shows status updated but counter not updated — contradiction... unless noteOn's then didn't run: `if (!audioReady || !poly) return;` audioReady is true... poly is built. held[note]? false. So paint should run.

Wait — did pointerdown actually hit the key? Click at (368,350): C4 white key range is x 336-400? Board starts at 326? In the screenshot, C4 white key is roughly x=337..399, y=173..393. (368,350) is inside. pointerdown → ensureAudio + noteOn.

Hmm, but the first click on the page: my window-level {once} listener also calls ensureAudio. No problem.

Why is the counter 0? Let me think: noteOn is called; ensureAudio() — audioReady is false, activating is false → set activating=true, return Tone.start().then(...). noteOn chains .then onto that Promise. Inside ensureAudio's then: buildVoice(), audioReady=true, activating=false, status update. Then noteOn's then: audioReady true, poly exists, held false → held=true, triggerAttack, paint(true) → started=1. Then pointerup → noteOff → released=1, held list empty. Final DOM: started 1 · released 1. But display shows 0 · 0!

Unless... paint's counter code: `if (on) started++; else released++;` no problem.

Maybe the click's pointerdown happened before... wait, status shows "Audio active — state: running" — that's set in ensureAudio's then. So the chain ran. noteOn's then must have run after. Unless noteOn wasn't called at all! Because pointerdown handler: `var el = e.target.closest ? e.target.closest(".key") : null;` e.target is the key's div... closest exists. dataset.note exists. Then noteOn.

Hmm — but wait: the earlier first click (before the shim edit) incremented? I didn't have the counter then.

Or: exception inside noteOn's then? poly.triggerAttack(note, Tone.now()) — Tone.now() is fine. If an exception is thrown inside the Promise .then callback, it's swallowed (unhandled rejection) — and an unhandled rejection should show in console! Console shows nothing new. Hmm, unhandled rejections show as errors in console. Not present.

Or paint threw? heldEl exists.

Wait a moment — maybe the issue is: two ensureAudio calls race: window's once listener (pointerdown on window) fires before board's pointerdown? Order: window listener is on window (bubble phase: board's handler runs first during bubbling at board, then window). board's pointerdown calls ensureAudio → activating=true, returns Promise P1. noteOn chains onto P1. Then window's once pointerdown calls ensureAudio → audioReady false, activating true → returns Promise.resolve()! Then noteOn... no wait, noteOn is only called from board's handler with P1's chain. No problem.

But board's pointerup → endPointer → noteOff(note): held[note] — at the moment pointerup fires (synchronously right after pointerdown in synthetic click?), held[note] is still false (P1 unresolved) → noteOff returns without releasing. Later P1 resolves → noteOn's then: held false → triggerAttack → note starts and stays held forever! But then counter should show started 1, Held: C4. Display shows Held: — and started 0.

So noteOn's then really didn't run, or returned early. `if (!audioReady || !poly) return;` — audioReady is set in ensureAudio's then... but which ensureAudio's then? P1's then sets audioReady=true. noteOn's then is chained after that. Should be true.

Unless buildVoice threw! If buildVoice throws inside ensureAudio's then, audioReady stays false, activating stays false... but status shows "Audio active — state: running"?? That's set after buildVoice in the same then. If buildVoice threw, status wouldn't update. Status did update. So buildVoice succeeded.

Hmm wait, status text: "Audio active — state: running" — yes, it's displayed.

So noteOn's then: audioReady true, poly truthy, held[note] false → proceed... paint increments started. Counter shows 0.

Unless noteOn wasn't called because pointerdown's target wasn't a key: e.target might be the board? Click at (368,350) — inside C4 key. closest('.key') finds it.

Or: the click tool dispatches mousedown/mouseup without pointer events? If the tool synthesizes only mouse events (not pointer events), my pointerdown handler never fires! But then how did audio activate? Via window's once listener for "keydown"/"pointerdown"... those are also pointer/key. Hmm, audio activated on this click — via which handler? If pointer events don't fire, ensureAudio isn't called... unless the click tool dispatches real input (CDP Input.dispatchMouseEvent generates pointer events in Chrome). Chrome generates pointerdown from mouse input. So pointer events do fire.

Wait, maybe the issue is the earlier drag test: after drag, pointer capture... unrelated, page was reloaded.

Let me look at the counter DOM again: "started 0 · released 0". And Held: —. Status: active running.

Hypothesis: click's pointerup arrived before Tone.start() resolved (likely, synthetic click is instantaneous). noteOff early-returns (held false). Then P1 resolves → noteOn's then runs → held[C4]=true, triggerAttack, paint → started=1, Held: C4 — and never released (pointerup already consumed)! Then DOM should show Held: C4, started 1. Not observed. So noteOn's then didn't run at all.

Why? ensureAudio returns `Tone.start().then(...)`. noteOn does `ensureAudio().then(cb)`. But look at ensureAudio: `if (audioReady || activating) return Promise.resolve();` — on board's pointerdown: first call → activating=true... then window's once listener fires (bubbling to window after board's handler) → ensureAudio again → activating true → returns Promise.resolve() — harmless.

Hmm, but actually wait: which fires first — window's once listener is added with window.addEventListener(type, once) — bubble: target → ... → board → document → window. board's handler first. OK.

So P1 = Tone.start().then(setReady). noteOn chains cb onto P1. Microtasks: after Tone.start resolves, setReady runs, then cb. Both run. cb: audioReady true...

Unless `held[note]` was true?! If held[C4] were true from a prior test (pre-reload)? No, reloaded.

I'm going in circles. Let me add console logs temporarily? Better: use inspect after clicking again (audio already active now — synchronous path). Click C4 again and inspect: if counter increments to 1/1, then the note path works when audio is already ready; the first click's issue is the race: pointerup before Promise resolution → noteOff is no-op; then noteOn's then starts the note → stuck... but not observed.

Hmm, actually maybe observed: after this click, is a note stuck right now? Held shows —. No.

New hypothesis: exception in noteOn's cb → unhandled rejection → console error. Console shows no new entries... but maybe console snapshot only shows page load messages? Previous snapshots did show new messages? All messages identical across reloads (load-time ones). Click that activated audio produced status change but no new console entries — consistent.

If an unhandled rejection occurred, Chrome logs "Uncaught (in promise) Error...". Not present. So no exception.

Therefore noteOn's cb ran and paint ran → started should be ≥1... unless paint's counter lines didn't execute due to early return? paint: toggles class, chip, then `if (on) started++; else released++;` then list... heldEl.textContent... countsEl.textContent. If paint ran with on=true, countsEl shows "started 1 · released 0", then noteOff's paint(false) → "started 1 · released 1". Display shows 0·0 → paint never ran → cb didn't run or returned early at `if (!audioReady || !poly) return;` or `if (held[note]) return;`.

held[note] true?? If held[C4] were true, noteOff on pointerup would release and paint(false) → released=1 → counter 0·1. Not observed.

So cb didn't run, or !audioReady/!poly. !poly: buildVoice assigns poly = new Tone.PolySynth(...).toDestination(); — does .toDestination() return the synth? In Tone v14, .toDestination() returns `this`. Yes.

!audioReady: set right after buildVoice in same then...

Oh wait. Got it: inside ensureAudio's then we set `audioReady = true; activating = false;` — but noteOn's cb is chained onto the Promise returned by ensureAudio(), which is `Tone.start().then(fn)` — fn's return value is ignored, chain continues. No problem.

Hmm, but actually: was noteOn called at all? board's pointerdown handler: `ensureAudio();` then closest... `if (!el || !el.dataset.note) return;` e.target — with pointer capture? No.

Let me test empirically: click again now (audio ready, synchronous path) and inspect counter.

The second click: started 1 · released 1. So the note path is working. The first click (the one that activated audio) lost the note. Because pointerup arrived before Tone.start() resolved → noteOff became a no-op, and then noteOn's deferred callback started the note... but then it should have stayed held (Held: C4, started 1). Observation is started 1 released 1 — this is consistent with only the second click being counted. So on the first click, noteOn's callback never fired even once? Or did it fire after the second click? Hmm.

The actual race on click 1: pointerdown → noteOn → ensureAudio P1 pending. pointerup → noteOff: held is false → no-op (and doesn't record the pending release). P1 resolves → noteOn's callback: held[C4]=true, attack, paint → started=1, Held: C4 stuck!

But after click 1, the DOM showed started 0 · released 0 and Held: —. Contradiction... unless P1 resolved between the click 1 snapshot and click 2? No: the click 1 snapshot already showed status "Audio active" (set in the same then before the callback? No! status is set in ensureAudio's then; noteOn's callback is chained after that; both are microtasks within the same turn — the snapshot is much later).

Hmm, wait, but maybe on click 1 the stuck note got released by click 2's pointerdown? No, click 2's pointerdown on C4: noteOn → held[C4] is true → early return (no double). pointerup → noteOff → release, paint(false): released=1... and started should be 1 from the stuck start. Click 2 snapshot: started 1 released 1 — consistent with: click 1 started the stuck note (started=1, Held C4), but the click 1 snapshot showed 0·0 and Held —...

Unless the click 1 snapshot was captured before P1 resolved (Tone.start() can take ~100ms+; screenshot at +0ms frame right after the click). Status "Audio active" was displayed... hmm, that means P1 had resolved by snapshot time. Ugh.

Wait, re-read the click 1 result: status "Audio active — state: running", Held: —, started 0 · released 0. If P1 had resolved, ensureAudio's then ran (status). noteOn's callback is a separate microtask chained on P1 — runs immediately after ensureAudio's then within the same microtask queue drain. The DOM snapshot (taken via CDP after the action) should be after both. So the callback ran → started=1 & Held C4 (since pointerup was before). Observation is the opposite.

Or pointerup arrived after P1 resolved: sequence: pointerdown (P1 pending), P1 resolves (status active, then callback: held=true, started=1, Held C4), then pointerup → noteOff → released=1, Held —. Final: started 1 released 1, Held —. But click 1 snapshot showed 0·0!

So neither. Something prevented the callback on click 1 but allowed it on click 2? On click 2, audioReady is already true: ensureAudio returns Promise.resolve() → callback is a microtask → runs synchronously-ish before pointerup? pointerup is a separate task; the callback's microtask runs right after the pointerdown task → held=true before pointerup.

On click 1: callback deferred until Tone.start resolves. Between pointerdown and resolution, pointerup fires → noteOff no-op. After resolution: callback → held=true, started=1, stuck. Click 1 snapshot showed 0·0 → callback hadn't run yet at snapshot time, but status was active?! Status is set in the same chain before the callback...

Ah, wait. Now I see! Inside ensureAudio: `return Tone.start().then(function(){...})`. Inside noteOn: `ensureAudio().then(function(){...})`. But the window's once-listener also calls ensureAudio() on the same pointerdown (bubbles to window after the board handler). Board handler runs first: ensureAudio #1 → activating=true, returns P1; noteOn chains cb1 to P1. Window once: ensureAudio #2 → activating is true → returns Promise.resolve() — no chain. No problem.

Hmm, so cb1 is chained to P1...

Let me look at noteOn's code once more:

function noteOn(note){
    ensureAudio().then(function(){
      if (!audioReady || !poly) return;
      if (held[note]) return;
      held[note] = true;
      poly.triggerAttack(note, Tone.now());
      paint(note, true);
    });
}

And ensureAudio's then sets audioReady=true...

Wait — maybe on click 1, `Tone.start()` resolved, ensureAudio's then ran: buildVoice() → `new Tone.PolySynth(...)` — creating a PolySynth before... no, after resume, no problem.

Hmm, but what about `poly.triggerAttack(note, Tone.now())` throwing? In that case paint wouldn't run (started stays 0), held[C4] stays true → stuck held flag; then click 2's pointerdown: noteOn → held true → return; pointerup → noteOff → held false, paint(false) → released=1 → counts 0·1. Observation is 1·1. So on click 2 paint(true) ran (started=1). Therefore triggerAttack didn't throw on click 2. On click 1 if triggerAttack threw → unhandled rejection in console (none) and held stuck → click 2's noteOn would early-return → started stays 0. Observation is started 1 on click 2 → held was false at click 2 → click 1's callback either fully ran (paint true → started 1 at click 1 time, contradicts snapshot) or never ran at all.

=> Click 1's callback never ran, yet status was updated. The only way: the Promise noteOn chained wasn't P1's settled chain... i.e., ensureAudio() inside noteOn returned Promise.resolve() because audioReady||activating was true at that moment! When could activating be true before the board handler's ensureAudio? If the window's once-listener ran first. Capture phase? No, bubble: board before window. Unless the click tool dispatches events such that the board handler doesn't run on pointerdown but the window listener does? E.g., the tool dispatches pointerdown only on window? Hmm, CDP's Input.dispatchMouseEvent delivers to the hit-test target and bubbles.

Or: the once-listener also listens for "keydown" — no key yet.

Or: on click 1, the board's pointerdown handler threw before noteOn? `ensureAudio();` first line — no. `e.target.closest` no issue.

Hmm, wait: maybe on click 1 the board handler's ensureAudio started P1 (activating=true). noteOn chains cb1 to P1. pointerup: noteOff no-op. Window once pointerdown: ensureAudio #2 → Promise.resolve(). P1 resolves later: ensureAudio's then #1: buildVoice, audioReady=true, status. cb1: audioReady true, poly set, held false → held=true, triggerAttack, paint(true) → started=1, Held C4. Stuck until click 2's pointerup releases (released=1, Held —). Click 2 snapshot: started 1 released 1, Held —. ✓ Matches click 2 snapshot!
Click 1 snapshot: showed status active + 0·0 + Held —. For that, at snapshot time P1 hasn't resolved yet (status should still be "Starting audio…"...). But status showed active. ✗.

Unless the status element's text I saw was from click...? Hmm, the click 1 snapshot's status: "Audio active — state: running". Hmm, hmm.

OK, enough theorizing, let me measure: add temporary console.log to noteOn/noteOff/ensureAudio paths, reload, click once, read console. Fast and definitive.

Also, I'll add logs to ensureAudio's then and catch as well. Let me add them right away.

Wait: ensureAudio's catch only catches errors from Tone.start() (buildVoice is inside then, and errors there also propagate to catch — good, they'll get logged).

Reload and click once.

Next, click once on C4 and read the console log.

Now it's clear! Log order:

1. `[dbg] noteOn request C4 audioReady= false`
2. `[dbg] noteOn cb C4 audioReady= false poly= false held= false` ← the callback ran while audioReady was still false!
3. `[dbg] noteOff request C4 held= false`
4. `[dbg] Tone.start resolved`

So noteOn's callback ran before ensureAudio's then?! How? Because ensureAudio returned `Promise.resolve()`?? No wait — the callback log shows audioReady=false poly=false, meaning the chained Promise resolved before Tone.start resolved. That happens if ensureAudio() returned an already-resolved Promise: the guard `if (audioReady || activating) return Promise.resolve();` — activating was TRUE at the point noteOn called ensureAudio! Because the board's pointerdown handler first calls `ensureAudio();` (line 1) → activating=true, P1 pending. Then it calls noteOn → ensureAudio #2 sees activating=true → returns Promise.resolve() → callback runs on the microtask with audioReady still false → returns. The note is lost.

Fix: noteOn should not call ensureAudio again; it should chain onto the same activation Promise. Restructure: ensureAudio returns a cached Promise `audioPromise`.

let audioPromise = null;
function ensureAudio(){
  if (audioReady) return Promise.resolve();
  if (!audioPromise){
    audioPromise = Tone.start().then(...).catch(err => { audioPromise=null; ... });
  }
  return audioPromise;
}

Then noteOn: ensureAudio().then(cb) — cb runs after activation completes regardless of timing. Also, handle the release-before-activation race: pointerup before activation completes → noteOff sees held false → no-op; then activation's cb starts the note → stuck. Fix: track pending releases: in noteOff, if !held[note], record `releasedWhilePending[note]=true`? Better approach: maintain a `wantDown` state separate from `held`:

Simplest and most robust: keep a `pressed` set (intent) and a `held` set (sounding). noteOn: pressed[note]=true; ensureAudio().then(()=>{ if(pressed[note] && !held[note]) start }); noteOff: pressed[note]=false; if(held[note]) stop. This handles both races: release before activation → pressed false → cb doesn't start.

Also keydown repeat guard: use held or pressed? pressed (intent) — keydown repeat: pressed already true → noteOn called again → cb: pressed true, held true → skip. Fine, plus the e.repeat guard.

Rewrite noteOn/noteOff:

var pressed = {};
function noteOn(note){
  pressed[note] = true;
  ensureAudio().then(function(){
    if (!audioReady || !poly) return;
    if (!pressed[note] || held[note]) return;
    held[note] = true;
    poly.triggerAttack(note, Tone.now());
    paint(note, true);
  });
}
function noteOff(note){
  pressed[note] = false;
  if (!held[note]) return;
  held[note] = false;
  paint(note, false);
  if (poly) try{ poly.triggerRelease(note, Tone.now()); }catch(e){}
}

And ensureAudio with cached Promise:

var audioPromise = null;
function ensureAudio(){
  if (audioReady) return Promise.resolve();
  if (audioPromise) return audioPromise;
  activating = true; status...
  audioPromise = Tone.start().then(function(){ buildVoice(); audioReady=true; activating=false; status...; }).catch(function(err){ audioPromise=null; activating=false; status...; });
  return audioPromise;
}

Note: after catch, audioPromise=null so retries are possible.

Also allOff uses held — no problem; should it also clear pressed? On blur, clear pressed too so that a note whose key is still physically held down after refocus doesn't retrigger... keyup will fire anyway. Clear pressed in allOff as well.

Remove debug logs too. Apply the edits.

Also, the keydown handler: `if (e.repeat) return;` is placed after preventDefault — good. However, noteOn when already pressed (auto-repeat is already blocked by e.repeat). Also, pointer glissando: noteOff(current) sets pressed to false; noteOn(over) sets pressed. No problem.

One more point: keydown when the key is already pressed (e.repeat is false but pressed is true, e.g., two different physical... impossible). No problem.

Also, the `held` object is initialized as {} — Object.keys works.

Reload and test: click C4 (the first activating click) → the counter should display 1·1. Next, keyboard test: press 'w' → 2·2. Then drag for glissando. Then, temporary hold test for visual highlight.

Next, test the first activation click: click C4 → the counter should become 1·1.

Still 0·0 on the activation click! Why? Sequence: pointerdown → board handler: ensureAudio() → creates audioPromise (pending). noteOn(C4): pressed=true; ensureAudio() returns the same pending promise; .then(startVoice). pointerup → noteOff: pressed=false; held false → return. Promise resolves → activation's then: buildVoice..., then `Object.keys(pressed).forEach(if pressed[n] startVoice)` — pressed[C4] is now FALSE (released during activation) → correctly doesn't start (user already released!). Then startVoice(C4) in noteOn's then: pressed false → return. Correct behavior! The user released before the sound was ready; not starting is definitely correct (note ended). The earlier "stuck" concern is resolved; and losing the note on a super-fast click during activation is acceptable/correct semantics (key already released).

So current behavior is correct: a click that completes entirely before audio is ready produces no sound — physically analogous. Good. Counter 0·0 is honest.

But hmm — is it desirable that the activation click produces no sound at all? For a human, the click lasts ~100ms; Tone.start typically resolves in less than that? Here the synthetic click is instantaneous (down+up in the same ms), so the release precedes activation. A human click would likely still be held. Acceptable.

Alternatively, we could sound notes that were pressed and released during activation as a short blip — unnecessary.

Next, verify that normal operations work: click again (audio ready): expect 1·1. Then keyboard 'w': 2·2. Then drag glissando C4→E4: multiple starts. Then hold test.

Mouse click: 1·1. Next is the keyboard: press the "w" key (C#4), then drag from D4 to F4 for a glissando. After that, a temporary visual test of the hold.

inKeyboard W → 2·2. Next, drag from D4 (x≈468) to F4 (x≈602) at y=350: glissando D4→E4→F4, expecting 3 start/stop pairs → total 5·5.

Glissando: 5·5 (D4, E4, F4 were played and released). In the screenshot, you can even see a faint glow remaining on F4 (release transition).

Next, visual verification of the highlight during hold and polyphony (3 or more simultaneous notes). Temporary test: add a script that, after audio is ready, holds C4+E4+G4 for about 2.5 seconds via __piano, then take a screenshot during that time. Add a temporary block, reload, click to activate (or call ensureAudio via a click), wait, then screenshot.

Plan: temporarily add the following at the end of the IIFE:

window.__holdTest = function(){ ["C4","E4","G4"].forEach(function(n){ noteOn(n); }); setTimeout(function(){ ["C4","E4","G4"].forEach(noteOff); }, 4000); };

Then in the browser: reload → click somewhere (activate) → then... need to call __holdTest — but there's no evaluate action! Hmm. The browser tool can't run arbitrary JS.

Alternative: make the temporary test auto-run on load after the first gesture: e.g., a temporary listener: on the first pointerup, start a 3-second hold of the chord. Then: reload, click (activation + trigger), screenshot immediately → the held chord is visible.

Temporary code:
window.addEventListener("pointerup", function onceTest(){ window.removeEventListener... setTimeout(function(){ noteOn("C4"); noteOn("E4"); noteOn("G4"); setTimeout(function(){ noteOff("C4"); noteOff("E4"); noteOff("G4"); }, 3000); }, 300); }, {once:true});

Then reload → click a key → wait → screenshot shows 3 keys highlighted + Held: C4 E4 G4 + started 3 released 0. The screenshot action is right after the click: the click result's screenshot is at +0ms; the hold starts at +300ms. Then call the screenshot action again (a separate call, about 1 second later) → capture mid-hold. Then another screenshot after 4 seconds → released.

Execute.

The counter will display started 3 · released 0 during the chord playback. Reload, click, then take a screenshot during the hold (the second call).

Next, click somewhere (e.g., the header area at (600,60)) to trigger the test, then immediately take a screenshot to catch the code being held (the hold starts 300ms after pointerup and lasts 3 seconds). The screenshot of the click itself is at +0ms, so a second screenshot call is needed during the hold.

Next, take a screenshot during the hold (the code starts about 300ms after pointerup and is held for 3 seconds). The screenshot call happens right now.

Missed the 3-second window (screenshot shows started 3 · released 3 — the chord was played and released; polyphony of 3 simultaneous notes confirmed via counter: 3 starts with 0 releases in between... actually the counter alone can't prove simultaneity, but the code held all three: during the hold, Held should have shown 3 notes; the final 3·3 proves each was started and released exactly once).

Still want visual evidence of the highlight. The screenshot call took longer than 3 seconds? The screenshot shows released 3, meaning more than 3.3 seconds elapsed between click and screenshot. Tool call latency is large. Retry with a longer hold: edit the temp test to a 20-second hold? Then click, screenshot — even with latency, it should fall within the window. Let's bump it to 20 seconds and also start immediately (100ms).

Note: A#4 is a black key — good, we can test the black key highlight too. 4 simultaneous notes ≥ 3. Reload, click, screenshot.

Next, click on the header (600,60) to trigger it, then take a screenshot. The hold is currently 20 seconds.

Interesting point: the DOM text shows "Held: C4 E4 G4 A#4 / started 4 · released 0" (the code is currently being held), but the attached screenshot (taken at +0ms of the click) shows the pre-hold state. The DOM snapshot is newer than the image. Take another screenshot right now to capture the highlighted keys.

Excellent! Visual confirmation complete: C4, E4, G4 (white keys) and A#4 (black key) are highlighted in blue while being held; the legend chips A, D, G, U are also highlighted; "Held: C4 E4 G4 A#4", "started 4 · released 0" — 4-note simultaneous polyphony with highlights.

Next, remove the TEMP-TEST block, reload, and do a final sanity check: click + key operations, verify the console is clean, and confirm the release after the hold ends (wait 20 seconds? No — since we're removing the test, the hold won't occur). Also confirm that the temp chord releases: it's scheduled to release at +20 seconds on the current page; but we're going to reload anyway.

Remove the temp block.

Finalize: reload once to confirm the final file works (click → audio enabled, notes play, console is clean except for the expected autoplay warning before gestures). After that, report back.

The final file is in a clean state. One last simple operation check: click a key to confirm that notes still play on the final artifact (counter 1·1), then finish. In reality, there's already sufficient coverage, but doing one final click on the saved file is low-cost and can confirm that no test code remains and that playback works.

This click was the activation click (first gesture after reload), and since it completed before Tone.start resolved, no note was produced (as designed, correct behavior: the key had already been released). Audio is currently active. There's no more time to spare for additional clicks, but this behavior was already verified earlier in this same final code path (the 1·1 click after activation was performed on code identical except for the test hooks... actually, the 1·1 verification was before adding/removing the temporary hooks, but the note logic hasn't been changed since the ensureAudio fix. The post-fix verification sequence (click 1·1, key 2·2, drag 5·5, chord 4-hold) was all run on code identical to the final version except for the temporary test block that was added and then removed. The temporary block only added listeners, and its removal doesn't affect the logic.

One consideration: the first activation click producing no sound is by design (release precedes readiness). No problem.

The file is saved. Wrapping up.