mesh-tap-symphony

Peer-to-peer mesh: each phone is one drum; 30 seconds of taps records a synced loop that replays on every phone.

Live: https://baditaflorin.github.io/mesh-tap-symphony/

Each phone is one drum sound — kick, snare, hi-hat, clap, cowbell, rim. Tap the screen to play your sound. Every tap, from every phone, is appended to a shared 30-second loop. The loop runs on every phone simultaneously, so the group accidentally composes a beat together.

Try it: open the link in two browser tabs, pick a different drum in each, hit Join the band, and tap. Each tab hears both drums replay together every 30 seconds.

How it works

1. Yjs over y-webrtc, clock-synced (median offset, ~10–30 ms).
2. The 30-second loop is anchored to mesh time: loopT = meshNow() % 30000.
3. Each tap is appended to a shared Y.Array<{ slot, dt, id }>, where dt is the position inside the 30-second loop in milliseconds.
4. Every phone, every frame, looks at incoming tap events whose dt is about to be crossed and schedules them through Web Audio at currentTime + (dt - loopT)/1000. Sample-accurate playback locally; mesh-time-synchronized across phones.

The loop is rolling — your taps replay every 30 seconds until someone hits Clear loop for everyone (it wipes the shared loop on all phones). The track view at the top shows everyone's marks; your own slot's marks are highlighted in your accent color.

Drums

Slot	Synthesis
kick	sine, 140→40 Hz exponential drop, 0.4 s decay
snare	high-passed white noise, 0.18 s
hi-hat	high-passed noise, 0.05 s
clap	4 short noise bursts spaced 10 ms
cowbell	dual square wave at 800/540 Hz
rim	very short hi-hat

All synthesized in Web Audio — no samples, no network, no licensing.

Privacy threat model

See docs/privacy.md. What's on the wire: per-tap { slot, dt: ms-into-loop, id: uuid }. Plus the usual clock-sync timestamps. No audio is transmitted; every phone synthesizes from the tap metadata.

Architecture

• Mode A — pure GitHub Pages.
• WebRTC — Yjs + y-webrtc with self-hosted signaling and TURN.

Run it locally

git clone https://github.com/baditaflorin/mesh-tap-symphony.git
cd mesh-tap-symphony
npm install
npm run dev

Self-hosted infrastructure

Repo	Endpoint	Role
signaling-server	wss://turn.0docker.com/ws	y-webrtc protocol fan-out
turn-token-server	https://turn.0docker.com/credentials	HMAC TURN creds
coturn-hetzner	turn:turn.0docker.com:3479	TURN relay

ADRs

• 0001 — Deployment mode
• 0002 — Rolling 30-second loop on mesh time
• 0003 — In-browser drum synthesis
• 0010 — GitHub Pages publishing

License

MIT © 2026 Florin Badita