Continuous pitch · Two-hand expression
Play a theremin online.
Glide from one pitch to the next. Move your right hand sideways to change pitch and raise your left hand for volume, or hold and drag on the touch pad.
Right hand: move sideways for pitch. Left hand: raise for volume.
Camera stays off until you choose Start camera.Drag on the pad for a continuous glide. For keyboard access, use Play tone with sliders, then adjust each slider with the arrow keys.
Camera frames are processed on this device. No microphone is requested. Start at a comfortable speaker volume.
How to play this virtual theremin
- 01
Hear the glide
Hold and move on the touch pad. Moving right raises the pitch; moving up increases the volume. Release the pad to stop. You can use this mode without granting camera access.
- 02
Try the hand controls
Choose Start camera and allow video access. Keep both hands visible and separated. Move your right palm across the mirrored view to sweep the pitch from C3 to C6; raise your left palm to increase volume.
- 03
Shape a phrase
Lower your left hand to soften a note, move your right hand to the next pitch, then raise the left hand again. Remove either hand from view to mute camera playback. Stop sound & camera ends the session.
For keyboard access, activate Play tone with sliders. Tab to Pitch or Volume and use the arrow keys. Mute slider tone stops the sound. The frequency display shows the current pitch in hertz.
Practice a steady note, then a smooth slide
Start quietly. Hold a pitch near 440 Hz and keep your right hand still while you change volume with the left. Then move your right hand slowly to hear a continuous slide. Unlike a piano, there are no fixed keys to snap to.
The range spans three octaves, about 131–1047 Hz. Each octave doubles the frequency: 220 Hz, 440 Hz and 880 Hz are all A notes. Try sliding between them without letting the volume jump.
What makes it a theremin-style instrument?
A traditional theremin controls pitch and volume without physical contact. This browser version uses a camera or touch input in place of antennas and produces one continuous electronic tone. It keeps pitch and volume independent so you can practice glides and expressive phrasing.
The sound is a synthesized sine wave. Hand tracking and browser audio are different from the electrical response of a hardware theremin, so this is a virtual instrument for experimentation rather than a hardware calibration simulator.
For distinct notes with a struck tone, try the air piano. For several notes in one chord, use Gesture Synth. The gesture music guide compares all three approaches.
Online theremin questions
Does the pitch snap to piano notes?
No. The oscillator moves continuously between frequencies, including pitches between semitones. The displayed hertz value is rounded for reading; the sound is not quantized to that display.
Why does camera mode need both hands?
The right palm controls pitch and the left palm controls volume. If either hand cannot be tracked reliably, the camera-controlled tone fades to silence. Keep both hands in view with even lighting, or use the touch pad and sliders.
Can I play this theremin for free without installing an app?
Yes. The instrument runs on this page without an account or installation. It needs Web Audio support; camera mode also needs video permission and hand-tracking support. Touch, mouse and slider controls work without the camera.
Is my camera or microphone recorded?
This theremin does not record your performance, upload camera frames or request microphone access. Hand tracking happens on your device. See the privacy policy for the site's analytics and advertising.