Arpeggiator pad · qwen3.8-27b
Using the pre-provided tone.min.js (global Tone), build a clickable pentatonic pad grid that triggers a synth voice with reverb, plus a play/stop button that runs an arpeggiator sequence at an adjustable tempo. All sound synthesized, no audio files.
transcript · 18 messages
Using the pre-provided tone.min.js (global Tone), build a clickable pentatonic pad grid that triggers a synth voice with reverb, plus a play/stop button that runs an arpeggiator sequence at an adjustable tempo. All sound synthesized, no audio files.
thinking
First, let's check the working directory and tone.min.js.
{"command":"ls -la /tmp/ws && head -c 300 /tmp/ws/tone.min.js"}total 344 drwxr-sr-x. 2 node node 25 Aug 15 13:47 . drwxrwsrwx. 3 root node 16 Aug 15 13:47 .. -rw-r--r--. 1 node node 349169 Aug 15 13:47 tone.min.js /*! For license information please see Tone.js.LICENSE.txt */ !function(t,e){"object"==typeof exports&&"object"==typeof module?module.exports=e():"function"==typeof define&&define.amd?define([],e):"object"==typeof exports?exports.Tone=e():t.Tone=e()}("undefined"!=typeof self?self:this,(()=>(()=>{var
thinking
Check the Tone version to get the API details.
{"command":"grep -o 'Tone.js/[0-9.]*' /tmp/ws/tone.min.js | head -2; node -e \"const T=require('/tmp/ws/tone.min.js'); console.log(T.versionTone.js/ 14.8.49 [ 'AMSynth', 'AudioToGain', 'AutoFilter', 'BiquadFilter', 'DuoSynth', 'FMSynth', 'FeedbackCombFilter', 'Filter', 'Gain', 'GainToAudio', 'JCReverb', 'LFO', 'LowpassCombFilter', 'MembraneSynth', 'MetalSynth', 'MonoSynth', 'NoiseSynth', 'OnePoleFilter', 'Pattern', 'PluckSynth', 'PolySynth', 'Reverb', 'Sequence', 'Synth', 'Transport', 'TransportTime', 'TransportTimeClass', 'Tremolo', 'dbToGain', 'getTransport' ]
thinking
Tone 14.8.49. In v14, Tone.Reverb is an async generator (needs await `reverb.generate()`? Actually in v14, Reverb requires `await reverb.generate()` before it can be used... in v14, Reverb became a user-space convolver, and the constructor is synchronous but you have to call `await reverb.generate()`. Yes, Tone 14: "Reverb.generate() must be called before the Reverb is used." Actually, was generate automatic in 14.x? Let me check: in Tone 14, Convolver and Reverb became async. The docs say "await reverb.generate()". Let me quickly check the minified source for "generate" on Reverb. Simpler: use JCReverb — no async needed. But the requirements say "with reverb" — JCReverb is also a reverb. Safer to use Reverb with await generate(), or JCReverb to avoid issues. Tone 14's Reverb: the constructor no longer pre-generates; needs `await reverb.generate()`. Actually, I recall that in Tone 14, Reverb automatically triggers generation in the constructor? Let me check the source.
{"command":"node -e \"\nconst T=require('/tmp/ws/tone.min.js');\nconst r=new T.Reverb();\nconsole.log('has generate:', typeof r.generate);\nNode.js v24.18.1 [Showing lines 3-3 of 3 (50.0KB limit). Full output: /tmp/pi-bash-f615793e0ac4322e.log]
thinking
Node fails (no audio context). Can't easily test. I'll write defensively: use Tone.Reverb, call `await reverb.generate()` before connecting (v14 API), with a fallback to catch errors. Actually, in Tone 14.8.49 the Reverb constructor signature is Reverb(decay, preDelay, wet). generate() is a user-space thing, and does `reverb.generate()` return a promise? Let me try grepping the minified source.
{"command":"grep -o 'generate()' /tmp/ws/tone.min.js | head -1; grep -o 'async generate[^{]*' /tmp/ws/tone.min.js | head -3"}generate()
thinking
Hmm, `generate()` exists. In v14, `reverb.generate()` returns a Promise (user-space processing). I'll write code like this: create the reverb, then after `await toneReady`, do `await reverb.generate()` before triggering the sound. Wrap it in try/catch.
Actually, to be even safer, use `Tone.OfflineContext`? No — keep it simple: call `await reverb.generate()` inside an async init after `Tone.start()`. If generate doesn't exist or fails, just proceed anyway.
Pentatonic grid: let's make 5 octaves x ... 5 notes x 4 octaves = 20 cells? C major pentatonic: C D E G A. Grid: columns = 5 notes, rows = octaves (4 rows, C3–C6). Clickable cells, on mousedown trigger the poly synth. Highlight on click.
Synth: PolySynth using Synth, warm pad-ish sound: type "fatsawtooth", attack 0.2, decay 0.5, sustain 0.4, release 1.5. Route: poly -> filter -> reverb mix (dry+wet) -> destination. Add slight detune and a lowpass filter that opens per note? Keep it simple.
Arpeggiator: play/stop button; Tempo slider (BPM 60–180). Use Tone.Part/Transport with a repeating pentatonic pattern. Either a random walk or a fixed pattern. Use a Transport schedule with a repeat loop, at a tempo from the slider. Pattern: e.g. [0,1,2,3,4,3,2,1] mapped to octaves, or use a Pattern with a "upDown" mode on the pentatonic notes. Use a Tone.Part that reads notes in 16th/8th notes.
Implementation:
- `Tone.Transport.bpm.value = tempo`; slider updates it live.
- `arpPart = new Tone.Part((time, note) => { poly.triggerAttackRelease(note, "8n", time, 0.8) }, arpNotes)` where arpNotes is a time/value array over 2 bars. Schedule repeat: `arpPart.start(0, 16)` (16 16th notes? set loop). Use Transport.scheduleRepeat to start the part... simpler: create the part once, `part.loop = true; part.loopEnd = "2m"; part.start(0);` and then Transport.start()/stop().
Also, should I add a "chord" mode? Keep the scope. Add keyboard support? Not required. Keep it: grid, play/stop, tempo slider.
Might add subtle visuals: cells light up when the arpeggiator plays them — nice touch: in the part callback, flash the corresponding cell. I'll include that.
Write index.html.
Tone 14.8.49 confirmed. In v14, `Reverb` requires an async `generate()` call — I'll handle that. Writing the app:
/tmp/ws/index.html (11312 bytes)Successfully wrote 11312 bytes to /tmp/ws/index.html
thinking
Wait — the arpPart's loopEnd: the ARP figure spans 0.0 to 4.875 in beats (5 beats). I set loopEnd to "4m" but the last note is at 4.875. A "4m" loop will repeat every 4 beats and cut off the last beat. I should set loopEnd to "5m" (5 beats). The values in ARP are in beats relative to the pattern's start position. Pattern duration = 5 beats. Fix loopEnd to "5m". Also, the grid's template-areas: I defined grid-template-areas but didn't assign grid-area to the cells — the cells are placed automatically in row-major order, so it's fine (C5 D5 E5 G5 A5 on the first row, etc.). The template-areas are unnecessary but harmless. The first row is C5..A5 (the highest octave at the top). The subtitle says "C2 top ... C5 bottom" but the actual order is C5 on top. Just a visual issue, but since the CSS's template-areas aren't being used, the cells fill in row by row in the order appended: row0 = C5..A5 on the top row. OK. Fix loopEnd to "5m".
One fix: the ARP figure spans 5 beats (0.0–4.875), so the loop end must be `5m`, not `4m`:
{"path":"/tmp/ws/index.html","edits":[{"oldText":" arpPart.loopEnd = \"4m\"; // 4 beats (one bar of 16ths) -> loops the 32-step figure","Successfully replaced 1 block(s) in /tmp/ws/index.html.
thinking
Quick sanity check: verify that there are no syntax errors in the inline script. Extract the script and run node --check.
{"command":"cd /tmp/ws && node -e \"\nconst html=require('fs').readFileSync('index.html','utf8');\nconst m=html.match(/<script>([\\s\\S]*?)<inline JS parses OK has tone.min.js ref: true no external urls: true -rw-r--r--. 1 node node 11292 Aug 15 13:55 index.html
thinking
Also, fix the inaccurate comment in the subtitle/CSS "C2 top...C5 bottom" — the grid is actually placed with C5 at the top. Minor point: should I delete the template-areas comment? It's fine, but the comment "C major pentatonic: C D E G A across 4 octaves (C2 top ... C5 bottom of grid)" is wrong — C5 is at the top. Easy to fix.
{"edits":[{"newText":" // C major pentatonic: C D E G A across 4 octaves (C5 top row ... C2 bottom row)","oldText":" // C major pentatonicSuccessfully replaced 1 block(s) in /tmp/ws/index.html.
thinking
Done. Summarizing. (Original text: "Done. Summarizing.")
Done — `/tmp/ws/index.html` is a single self-contained page (all CSS/JS inline, only external reference is the local `tone.min.js` script tag, no network resources). **What it does:** - **5×4 clickable pentatonic pad grid** (C major pentatonic, C2–A5, 20 pads showing note name + frequency). Clicking a pad triggers a synth voice and flashes the pad. - **Synth voice:** `PolySynth` with a 3-voice fatsawtooth oscillator (32° spread for warmth), soft ADSR (0.25s attack / 2.5s release) → lowpass filter (1200 Hz) → `Tone.Reverb` (6s decay, 45% wet) → destination. Handles the Tone 14 async `reverb.generate()` requirement and a fade-in to avoid a startup click. - **Play/Stop button:** runs a 32-step, 5-beat arpeggiator figure via a looping `Tone.Part` on `Tone.Transport`. The arpeggiator flashes the corresponding pads as it plays, and the button toggles between ▶ PLAY ARP and ■ STOP. - **Adjustable tempo:** 50–180 BPM slider that live-updates `Transport.bpm` while playing, with a readout and status line. - Audio engine starts on first user gesture (`Tone.start()`), satisfying browser autoplay policies. Verified: inline JS parses cleanly, Tone version confirmed 14.8.49, and no external URLs are referenced.
TAKE IT TO CODE
A single self-contained HTML file — copy it and open in any browser, or reuse the prompt with your own pi-agent run.
RUN
EVALUATION
Pentatonic pad grid renders with tempo slider, but clicking a pad throws an audio error 'Cannot read rampTo' instead of playing sound.
Vision grade · anthropic/claude-sonnet-5
MEASUREMENTS
Raw readings from the capture, not a verdict — the grade above is the only judgement. Percentages are how much of the screen changed; the measure under-reports sparse motion on a dark background.