I–VII
Choose a Root Degree With Your Left Hand
Move your left palm across seven lanes. The selected lane becomes a root from the current major scale: I through VII. A cyan pulse confirms the root after it stabilizes.
Browser instrument
Gesture Synth
Turn your webcam into an instrument. Move left for a root; show a right-hand shape for a chord.
Video stays on this device
Camera Off
InputWaiting
Camera is off
Click Start camera to begin
Root degree unavailable. Chord muted. Camera is off.
Move your left hand
Move your left palm across I–VII at any comfortable height and hold briefly.
Root degree—
- I
- II
- III
- IV
- V
- VI
- VII
Chord
Muted
Mute
How to play 60-second quick start
- 1
Choose CKeep the key on C. Move your left palm to lane I at any comfortable height and hold briefly.
- 2
Show one fingerFace your right palm toward the camera. Extend only your index finger and tuck your thumb.
- 3
Raise for soundLift your right palm for more volume. The chord readout should change from Muted to C.
Right-hand fingersChord shape
- 0Mute
- 1Major
- 2Minor
- 3Dominant 7
- 4Major 7
- 5Sus4
Left handMove your palm across I–VII at any comfortable height and hold briefly.
Right handMove your palm up or down for volume; left or right for a darker or brighter tone.
Still muted?Keep both palms and fingertips visible, separate your hands, and stay inside the comfortable center of the camera view.
Beginner challenge
Key C · C Major challenge
Play C → G → Am → F
Left handI → V → VI → IV
Right-hand fingers1 → 1 → 2 → 1
Press Start camera when you are ready. Your camera frames stay on this device.
Private by design: camera frames and recordings stay in your browser and are never uploaded.
Learn the gestures
Start making sound in three moves
Two hands, one camera, and a short path from motion to music.
01 The instrument
Live signal path
Local / readyPlay Music With Hand Gestures
Gesture Synth takes the shortest path from curiosity to sound. There is no account, download, microphone request, or setup wizard. Start the camera, keep both hands visible, and the instrument responds on this page. The live display shows what the tracker understands, connecting each movement to the chord you hear.
The left hand moves across seven root-degree lanes. The right hand chooses a chord quality by the number of extended fingers. Its vertical position shapes volume, while its horizontal position opens or closes the filter. Timing and smoothing keep uncertain frames from triggering new chords.
02 Definition
Motion becomes harmony
What Is a Gesture Synth?
A gesture synth replaces keys or pads with body movement. This browser version uses a webcam to locate hand landmarks, then turns stable signals—position, visible fingers, and motion—into musical instructions for the built-in synthesizer.
Camera, tracking, chord, volume, and tone stay on one stage, so the control system remains visible. If a hand leaves the frame, the interface identifies the missing role and mutes smoothly.
- Input
- Two-hand webcam tracking
- Mapping
- Position + finger count
- Output
- Browser-based synthesis
- Latency
- Processed on your device
03 Playing method
Your hands are the controls
Two-Hand Controls at a Glance
Use this on-stage map as a quick reminder while you play. For camera setup, hand positioning, a first progression, and tracking fixes, follow the full beginner guide.
0–5
Choose a Chord Quality With Your Right Hand
Make a fist to mute. One finger selects Major, two Minor, three Dominant 7, four Major 7, and five Sus4. Root and quality remain independent, leaving room for playful combinations.
X / Y
Control Volume and Filter
Raise your right palm for more volume and lower it for less. Move horizontally to change the tone filter. Smoothed values produce steadier swells with less audible stepping.
04 Control map
One grid, every chord
Chord Controls at a Glance
The key selector supplies seven I–VII root lanes from the current major scale. Your right-hand finger count applies Mute or a chord quality independently to the selected root.
Use the quick 0–5 map while playing. The complete chord guide adds an interactive 12-key reference, chord formulas, and beginner progressions.
Left handRoot degree
- I
- II
- III
- IV
- V
- VI
- VII
Right-hand fingersChord quality
- 0Mute
- 1Major
- 2Minor
- 3Dominant 7
- 4Major 7
- 5Sus4
05 Uses
Built for immediate play
Why Use This Gesture Synth?
Sketch an idea quickly
Explore timing, movement, and harmony without stopping to configure a conventional instrument.
Make harmony visible
Use the live root and chord readouts for classroom demonstrations or a first introduction to synthesis.
Keep processing local
The sound engine and hand tracking run on your device instead of waiting on a round trip to an AI service.
Capture a short performance
Fifteen-second local recording is optional; playing never depends on recording support.
06 Local processing
Privacy status
Camera Privacy and Browser Support
Gesture Synth requests webcam video only after you press Start camera and never requests microphone audio. Frames stay in the page for local analysis. A recorded performance uses a temporary browser file URL that disappears when you discard the take or close the page.
Current Chrome and Edge on desktop or Android provide the primary experience. Other browsers can play when camera, Web Audio, WebAssembly, and MediaPipe checks pass. If permission is denied, the page explains how to enable it and retry.
Read the full privacy policy- CameraStarts only after permissionLocal
- MicrophoneNo microphone requestOff
- UploadNo camera upload endpointNone
- Primary supportCurrent Chrome and EdgeReady
07 Help
Instrument support
Frequently Asked Questions
Camera, tracking, browser, and chord answers.
What is a gesture synth?
It is a synthesizer controlled by physical movement. This version converts webcam hand landmarks into root, chord-quality, volume, and filter controls.
How do I play Gesture Synth online?
Press Start camera, allow access, and place both hands in frame. Move your left hand between root lanes and use right-hand finger counts for chord quality.
Which hand controls the chord root?
Your left hand selects the root degree by horizontal position. Your right hand selects Major, Minor, Dominant 7, Major 7, Sus4, or mute.
Does Gesture Synth upload my camera video?
No. Frames remain in your browser for local hand tracking. The site has no camera upload endpoint, account, or cloud recording storage.
Does Gesture Synth work on mobile?
It targets current Chrome on Android and adapts the stage for portrait screens. Performance depends on the device, browser, lighting, and available memory.
Why can’t Gesture Synth detect my hands?
Use brighter, even light; move farther from the camera; keep all fingertips visible; separate your hands; and avoid a busy background. Then try again.
Which browsers support Gesture Synth?
Current Chrome and Edge are the main targets. Safari and Firefox can play only when their camera, Web Audio, WebAssembly, and MediaPipe capabilities pass at runtime.
Instrument ready