Scale degrees I–V
Raise one through five fingers to move through the first five scale degrees. The selected key at the top of the instrument sets the tonal center.
Complete control guide
How to Use Gesture Synth
Use your left hand to choose the harmony. Use your right hand to change the voicing, octave, filter and volume. Start with one steady shape on each hand, then add movement after the chord is stable.
01
Play your first chord
- Start the instrument. Open the homepage, click the play control, allow webcam access and keep both hands fully inside the frame.
- Choose harmony with your left hand. Hold up one finger for scale degree I. Keep the palm upright while the tracker settles.
- Shape sound with your right hand. Hold up one finger for a root-position chord, then raise or lower that hand to change volume.
02
Left hand: choose the harmony
Scale degree VI
Raise your index finger and pinky while keeping the middle and ring fingers down.
Scale degree VII
Use the VI shape, then extend your thumb.
Major or minor
Tilt your left palm inward for major harmony or outward for minor harmony. Use a small, deliberate tilt.
03
Right hand: shape the sound
One finger
Play the chord in root position.
Two fingers
Move to the first inversion.
Three or four fingers
Three fingers add a seventh. Four fingers create a dominant or diminished seventh color, depending on the selected harmony.
Thumb, height and tilt
Extend your thumb to shift up an octave. Move your hand higher for more volume, and tilt your palm to sweep the filter.
04
A simple practice sequence
- Select the key of C and the Warm Synth tone.
- Keep one right-hand finger raised at chest height.
- Move the left hand slowly through one, four, five and back to one finger.
- Repeat the sequence, then experiment with right-hand height and palm tilt.
05
Camera setup and tracking fixes
- Use front lighting. Face a window or lamp instead of putting the brightest light behind you.
- Leave room around both hands. Step back until wrists and fingertips remain inside the frame.
- Separate your hands. Avoid crossing them or placing one directly in front of the other.
- Make clean finger shapes. Half-raised fingers can cause the detected chord to flicker.
- Use a secure browser context. Camera access works on HTTPS deployments and localhost.
06
Privacy and browser requirements
This implementation processes camera frames locally in your browser and does not upload them. It requires JavaScript, webcam permission, Web Audio support and enough device performance for live hand tracking. A modern desktop browser gives both hands the most room; compatible mobile browsers can also work in landscape orientation.