What is a Gesture Synth?

A Gesture Synthesizer is an electronic musical instrument controlled by continuous physical motion rather than physical piano keys. Like the classical Theremin, pitch and timbre shift continuously based on spatial coordinates.

Is my webcam video recorded or sent to a server?

No. When Webcam Motion Mode is enabled, video frames are processed strictly in client-side memory using lightweight pixel frame-differencing. Zero video frames or personal images are ever stored or uploaded.

How does Scale Quantization work?

While a traditional theremin produces microtonal pitch glides that can sound out of tune, Scale Quantization snaps your gesture position to the nearest harmonic note in your selected scale (such as Pentatonic or Blues), ensuring every movement sounds musical.

Can I record and download my musical performance?

Yes. Click the 'Record Session' button in the toolbar. The tool captures your audio output in memory and lets you download an uncompressed 16-bit 44.1kHz stereo WAV file.

⚡ Play Electronic Music with Gestures, Motion & Touch

Gesture Synth: Interactive Web Audio Theremin Pad

Create expressive electronic melodies using hand motions, mouse drag, or mobile touch. Modulate pitch and resonant filters in real time with musical scale quantization, stereo delay, and live WAV audio recording.

Sound Presets:

Oscillator Waveform:

Scale Quantization:

Root Key:

Echo / Stereo Delay:

Note: -- Pitch: 0 Hz Filter: 0 Hz

Touch or click & drag inside the pad to play sound

Synthesis State Ready

Active Voices 0

Audio Latency < 10 ms

Motion Tracker Pointer / Touch

How to Play the Gesture Synth in 3 Steps

Choose Preset & Scale

Pick from atmospheric presets like Space Theremin or Ambient Glass, and select a musical scale (like Minor Pentatonic) to keep notes in harmony.

Touch, Drag or Wave

Move your cursor across the pad. Move left/right for pitch, and move up/down to open the lowpass filter and trigger resonance harmonics.

Record & Export WAV

Click Record Session to capture your live musical improvisation and download an uncompressed, studio-grade 16-bit WAV file directly.

The Complete Guide to Theremins, Gesture Synthesizers & Spatial Music

Physical gesture-based electronic instruments liberate musicians from mechanical keys and frets, offering an intuitive, continuous connection between physical motion and sound.

The Historic Legacy of Léon Theremin (1920)

Invented in 1920 by Russian physicist Lev Sergeyevich Termen (known as Léon Theremin), the Theremin was the world's first mass-produced electronic instrument. It relies on the principle of heterodyning:

The player's body acts as a grounded plate of a capacitor relative to two metal antennas.
One vertical antenna controls pitch: moving the right hand closer increases the frequency.
A horizontal loop antenna controls volume: raising or lowering the left hand attenuates the audio signal.
Because there is zero physical contact, the theremin creates evocative, otherworldly glissandi famously featured in classic science fiction cinema and rock music.

How Digital Gesture Synthesis Works

Modern browser architectures tap into the high-performance Web Audio API, replacing vacuum tube antennas with continuous two-dimensional $(X, Y)$ coordinate matrices:

Horizontal $X$-Axis (Pitch Carrier): Maps normalized coordinates ($0.0 \dots 1.0$) logarithmically to audio frequencies from 100 Hz up to 1,800 Hz.
Vertical $Y$-Axis (Biquad Filter & Brightness): Modulates a 24dB/octave resonant lowpass filter from 200 Hz up to 8,000 Hz, simulating acoustic brightness as you move upward.
Spatial Optical Differencing: When webcam tracking is engaged, an in-memory frame difference algorithm calculates the center of optical mass, translating physical hand waves into sound coordinates without tracking software or latency.

Musical Scales & Synthesis Waveforms Matrix

Reference guide for configuring scales, harmonic intervals, and oscillator timbres:

Scale / Waveform	Harmonic Structure	Musical Mood	Recommended Application
Minor Pentatonic	1, b3, 4, 5, b7	Soulful, safe, bluesy	Improvisation where every touch sounds musical
Sine Wave	Pure fundamental (no overtones)	Pure, whistle, ethereal	Classic space theremin, meditation glides
Sawtooth Wave	All integer harmonics ($1, 2, 3, 4\dots$)	Edgy, bright, brassy	Cyberpunk synth leads, filter sweep basslines
Arabic Hijaz	1, b2, 3, 4, 5, b6, b7	Exotic, dramatic, mystical	Middle Eastern cinematic soundscapes
Dorian Mode	1, 2, b3, 4, 5, 6, b7	Sci-Fi, modal jazz, contemplative	Ambient background drones and film scores

Frequently Asked Questions

How do I play chords on the Gesture Synth?

On mobile phones and touchscreens, our sound field supports multitouch. Placing two or three fingers down simultaneously triggers multiple independent synthesizer voices, allowing you to play rich ambient chords.

Does the webcam feature require installing any software?

No. The webcam feature runs entirely in client-side JavaScript using standard HTML5 video and canvas APIs. Video data is processed frame-by-frame in memory and is never uploaded, recorded, or transmitted to any server.

What is the difference between Chromatic and Quantized modes?

Chromatic/Free mode lets pitch glide continuously like a violin or original Theremin, including microtones. Quantized modes lock the pitch to specific scale notes (e.g. C, D, E, G, A in Pentatonic), so you can never play an out-of-key note.

Can I record my performance and use it in my music?

Yes. Clicking Record Session captures your audio stream. When finished, you download an uncompressed 16-bit 44.1kHz WAV file that is 100% royalty-free and ready to import into Ableton, FL Studio, or Logic Pro.