Termenvox

A gesture-controlled theremin in one HTML file. termenvox.vercel.app

Right hand steers pitch across the field, left hand rides volume — lift to swell, drop to hush (swappable for left-handed play). No camera? Drag in the field, or press K and play the keyboard piano-style. Camera frames are processed on-device and never uploaded.

Features

• Tuning — 18 scales, 6 temperaments (equal, just, Pythagorean, ¼-comma meantone, Werckmeister III, Kirnberger III), adjustable A₄, transpose, fine tune, and a grid-pull blend between free glissando and locked scale
• Voice — two oscillators with interval and detune, sub octave, breath noise, drive, filter, vibrato, tremolo, ensemble, ping-pong echo, generated hall
• Tracking — MediaPipe hands with 1€ smoothing, falling back to a built-in skin-blob tracker, then to pointer and keyboard
• MIDI out — continuous pitch bend and CC11 expression
• Recording, 6 presets, JSON export/import, and settings that persist

Every control explains itself: hover a label, tap it on a phone, or press What's this? to pin all the descriptions inline.

Shortcuts

Space hold · K keyboard · M mute · R record · C camera · L latch · F fullscreen · [ ] octave · 1–6 presets · Esc panic · ? help

Development

npm run dev    # http://localhost:4173 — a server is only needed for camera access
npm test

index.html is the whole application; deploying it is copying one file. The MediaPipe model is the only runtime fetch — without it the blob tracker takes over. The music maths lives in a dependency-free <script id="tvx-core"> block inside the page; test/core.test.mjs extracts that block and runs it under node:test.

Analytics

Optional, and off unless configured. npm run build — the Vercel build command — rewrites the <!-- umami --> block in index.html from the environment:

Umami is cookieless and collects no personal data. The build is idempotent, so running it without the variables strips the tag back out.

Licence

MIT