Gesture Synth: Play Music with Your Hands.
Gesture Synth is a free browser instrument that turns your webcam into a living chord pad and theremin. No controller, no install — just your hands and a webcam.
What You Can Do with Gesture Synth
Two Hands, Two Roles
Your left hand picks chords from I · vi · IV · V · ii — the same progressions behind countless pop songs. Your right hand controls volume, tone, and dynamics. Gesture Synth maps every gesture to a musical parameter.
Two Instruments, One Tool
Switch between Gesture mode (continuous chord pad) and Theremin mode (free-form pitch) without leaving Gesture Synth. Same hands, same camera, two very different sounds.
Three Sound Scenes
Pick a vibe in Play — Pop Pulse, Soft Ballad, or Retro Night. The same gestures inside Gesture Synth sound completely different. Switch anytime, no reload.
How to Play Gesture Synth
Gesture Synth maps every gesture from your two hands to a musical parameter. Learn the positions below and you're playing in under a minute.
Pick a chord from I · vi · IV · V · ii
The everyday chord progressions behind countless pop songs. Wrist tilt flips major and minor without lifting a finger.
- 1 finger upChord I
- 2 fingers upChord vi
- 3 fingers upChord IV
- 4 fingers upChord V
- 5 fingers upChord ii
- Index + pinkyChord VI
- Index + pinky + thumbChord VII
- Wrist tiltMajor ↔ Minor
Shape volume, tone, and chord style
Your right hand is the mixer — control energy, brightness, and octave without leaving Gesture Synth.
- Hand heightVolume (low → high)
- 1–4 fingers upTriad · inversion · 7ths
- Wrist tiltTone (filter sweep)
- Thumb extendedOctave down
- Fist (no fingers)Mute
- Mode switchGesture ↔ Theremin
Volume follows your right hand height
The Y-position of your right wrist sets the volume in real time — not your distance from the camera. Lift your hand to play louder, lower it to soften. To keep volume steady across a passage, anchor your elbow on the desk and hold your hand at a fixed height.
- Hand highFull volume
- Hand middleMedium volume
- Hand lowQuiet
Frequently Asked Questions
What is Gesture Synth?
Gesture Synth is a free, browser-based instrument that uses your webcam to track hand gestures and turns them into live music — chord pads, theremin tones, and more. It runs entirely on your device, with no install and no account.
How does Gesture Synth track my hands?
Gesture Synth uses MediaPipe Hand Landmarker — a Google open-source machine learning model that runs as WebAssembly inside your browser. Video frames are processed locally and never leave your computer.
Does Gesture Synth upload my camera video?
No. Hand tracking in Gesture Synth is fully on-device. Frames are processed locally and discarded immediately. No video upload, no telemetry, no cloud.
What chords can I play in Gesture Synth?
In Gesture mode, your left hand picks from I · vi · IV · V · ii — the most common progressions in popular music. In Theremin mode, you can play any pitch from roughly 65 Hz to 1200 Hz.
Does Gesture Synth work on mobile?
Currently Gesture Synth is optimized for desktop browsers (Chrome and Edge). Mobile support is on the roadmap.
Is Gesture Synth really free?
Yes. Gesture Synth is free forever. No subscription, no in-app purchases, no upsells. Just open and play.
Ready to Play with Gesture Synth?
Open Gesture Synth and play your first chord in under a minute. No install, no signup — just your hands, your webcam, and a browser.
Open Gesture Synth