Drum machine · qwen3.6-35b-a3b
Build a 16-step drum machine with a clickable grid for kick, snare, hi-hat, and clap, all sounds synthesized with the Web Audio API, plus play/stop and an adjustable BPM.
transcript · 6 messages
Build a 16-step drum machine with a clickable grid for kick, snare, hi-hat, and clap, all sounds synthesized with the Web Audio API, plus play/stop and an adjustable BPM.
thinking
The user wants a single-page drum machine web app with: - 16-step grid - 4 instruments: kick, snare, hi-hat, clap - All sounds synthesized with Web Audio API - Play/stop button - Adjustable BPM - All in one self-contained index.html file Let me build this step by step. I need to: 1. Create the HTML structure with a 16x4 grid 2. Style it with CSS 3. Implement Web Audio API synthesis for each drum sound 4. Add playback logic with timing 5. Add BPM control and play/stop For the synthesis: - **Kick**: Low-frequency sine wave with quick pitch envelope and amplitude - **Snare**: Noise burst + sine wave, mixed together - **Hi-hat**: Filtered noise (high-pass), short decay - **Clap**: Multiple noise bursts with specific envelope Let me write the complete file.
/workspace/index.html (13214 bytes)Successfully wrote 13214 bytes to /workspace/index.html
thinking
The file has been written successfully. Let me verify it exists and is complete.
{"command":"wc -l /workspace/index.html && head -3 /workspace/index.html && echo \"---\" && tail -3 /workspace/index.html"}490 /workspace/index.html <!DOCTYPE html> <html lang="en"> <head> --- </script> </body> </html>
thinking
The file is complete - 490 lines, proper HTML structure from `<!DOCTYPE html>` to `</html>`. Let me summarize what was built.
Done! `/workspace/index.html` is a fully self-contained drum machine. Here's what it includes: **Instruments (4 rows × 16 steps):** - **Kick** — synthesized sine wave with pitch drop + click transient - **Snare** — filtered noise burst + triangle tone - **Hi-hat** — high-pass/bandpass filtered noise, short decay - **Clap** — bandpass filtered noise with multi-burst envelope **Controls:** - **Play/Stop** button — starts/stops the sequencer - **BPM** — dual control via slider (40–240) and number input (synced) **UI details:** - Color-coded grid rows (red=kick, orange=snare, teal=hat, purple=clap) - Current step highlight (white outline) - Clicking an active cell plays the sound for preview - Uses Web Audio API `setInterval` lookahead scheduler for accurate timing - No external dependencies — runs completely offline/sandboxed
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
Static drum grid with play/BPM controls; grid cell toggled by drag but click, wheel, and keys had no visible effect.
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.