Gesture Synth – Play Music With Your Hands
Free, in your browser. Show your webcam a hand sign and hear a chord.
Play chords with your hands using your webcam — or with the keyboard and on-screen pads. Your video stays on your device.
Gestune is a free gesture synth that runs right in this page. Your left hand picks the chord with a simple finger sign, and your right hand shapes the sound: higher for louder, tilted for darker or brighter. There is nothing to install, no account to create, and you do not need to know any music theory to sound good.
Press Start Playing, allow the camera, and hold up one finger. You just played the first chord of the key. Upright, every chord in the sign table below belongs to the same key, so whatever you try sounds like it fits together. No camera? The keyboard and the on-screen pads play everything too.
How This Gesture Synth Works
Camera and on-device hand tracking
Your webcam picture goes to Google's MediaPipe hand model, which runs on your device inside the browser. It tracks the joints of each hand many times per second and works out which fingers are up and how the hand is tilted. The video is never uploaded or stored on a server.
Hands are assigned by where they appear on screen: the left half of the picture is your left hand. The view is mirrored, so moving your hand to the right moves it to the right on screen, just like a mirror.
From hand shapes to chords
Each finger count maps to a scale degree of the current key. In C major, one finger plays C, two plays Dm, three plays Em, four plays F, an open hand plays G, and so on. A synthesizer built into the page plays the notes, so the sound starts the moment you change shape.
Shapes have to hold for a few frames before they count, so a shaky hand will not make the chord flicker. If tracking drops for a split second, the sound keeps going instead of cutting out.
How to Make Music With Your Hands in 5 Steps
From a closed tab to your first chord progression in about a minute.
- 1
Press Start Playing
The sound engine starts first, then your browser asks for camera permission. Choose Allow. If you say no, you can still play with the keyboard or pads.
- 2
Step back so both hands fit
Sit about an arm's length from the camera with both hands in the picture. On a phone, turn it sideways.
- 3
Hold up fingers with your left hand
One finger plays chord I, two plays II, up to an open hand for V. Make a fist or drop the hand to go silent.
- 4
Raise your right hand for volume
Higher is louder. Tilt it to make the tone darker or brighter, and change its finger count to pick a voicing.
- 5
Try a progression
Move between 1, 5, 6 (index + pinky) and 4 fingers. It already sounds like a song. The short built-in tutorial walks you through the basics, and the Help button replays it.
Gesture Synth Chord Signs (Left Hand)
Your left hand chooses the chord. Upright gives the natural chord of the key. Tilt left past about 20 degrees to force minor, or tilt right to force major. Players who prefer it the other way can turn on Swap hands in settings.
| Left hand | Shape | Plays |
|---|---|---|
| Index finger up | I (C in C major) | |
| Index + middle | ii (Dm in C major) | |
| Index + middle + ring | iii (Em in C major) | |
| Four fingers, thumb tucked | IV (F in C major) | |
| Open hand (all five) | V (G in C major) | |
| Index + pinky (rock sign) | vi (Am in C major) | |
| Thumb + index + pinky | vii° (Bdim in C major) | |
| Fist or hand out of view | Silence | |
| Tilt left past about 20° | Force minor (e.g. IV → iv) | |
| Tilt right past about 20° | Force major (e.g. iii → III) |
Right Hand: Volume, Tone and Voicing
Your right hand is the expression hand. Height sets the volume and tilt sweeps a low-pass filter from warm to bright. If you take this hand out of view, its last settings are kept.
| Right hand | Shape | Does |
|---|---|---|
| 1 finger | Triad (closest inversion when Smooth chord changes is on) | |
| 2 fingers | First inversion | |
| 3 fingers | Second inversion | |
| 4 fingers | Seventh chord | |
| Thumb out | One octave lower | |
| Hand height | Volume (higher = louder) | |
| Hand tilt | Tone (darker ↔ brighter) |
Play Without a Camera
This gesture synth also works without a camera: hold a number key to sound a chord and let go to stop. On touch screens, use the on-screen chord pads. They support several fingers at once, and the "Hold to flip major/minor" button does what tilting does on camera.
| Key | Action |
|---|---|
| 1 – 7 | Play chords I – VII (hold to sound, release to stop) |
| Shift (hold) | Flip the chord between major and minor |
| Q | Triad |
| W | First inversion |
| E | Second inversion |
| R | Seventh chord |
Learn Real Songs, Chord by Chord
Open the Learn a song panel above the camera and pick a track. The instrument switches to the song's key and shows a hand-sign picture of the chord you need, plus the one coming next. If a chord has to be flipped, it tells you to tilt left or right.
In Follow mode the song waits until you play the right chord, so you can learn at your own pace. In Play-along mode you get four count-in clicks, then the chords run at the song's tempo. Each chord you hit on time turns green, and you get a score at the end. Hands, keys and pads all count.
Browse every song on the gesture synth songs page, or read the full hand sign tutorial first. No lyrics are shown, only chords. More songs are added regularly.
Songs You Can Play Today
Sounds and Settings
Pick a key and a sound, then tune how the gesture synth feels. Settings are saved in this browser only.
Warm Pad
Soft and slow. Great for ambient chord beds and slow ballads.
Glass Keys
A clear, bell-like keys sound that makes each chord change easy to hear.
Analog Saw
A buzzy synth tone with plenty of edge. Tilt your right hand to tame it.
Chord Harp
A bright, reedy organ-style tone inspired by the Omnichord, a natural fit for hand-played chords.
Key and scale
All 12 keys, in major or natural minor. Loading a song sets the right key for you.
Smooth chord changes
On by default. It picks the closest inversion of each chord so the notes glide instead of jumping.
Response speed
Fast, Balanced or Stable. Fast reacts quickest; Stable ignores more jitter in poor light.
View options
Swap hands, mirror the video, show the hand skeleton, or show the frame rate (FPS).
More Ways to Play
Tips for Smooth Hand Tracking
- Light your hands from the front. A window behind you makes your hands dark and harder to read.
- A plain background helps. Busy patterns or skin-colored walls can confuse the model.
- Keep your hands about an arm's length from the camera, with palms facing it.
- Spread your fingers clearly. Half-raised fingers are the most common cause of the wrong chord.
- Use desktop Chrome or Edge for the smoothest gesture synth frame rate. Safari works too, and phones work best held sideways.
- If chords flicker in dim light, set Response to Stable in settings.
Your Video Stays on Your Device
Hand tracking happens inside your browser. Camera video is not uploaded, saved or sent to any server, and recordings stay on your device until you choose to download them. There is no account and nothing to sign up for.
Your settings and whether you have seen the tutorial are kept in your browser's local storage. The site may use anonymous analytics and show ads; the privacy policy explains the details.
Gesture Synth FAQ
Is Gestune free?
Yes. Every feature, including songs, theremin mode and recording, is free to use in your browser with no sign-up.
Do I need to install anything?
No. It is a web page. Open it in a modern browser, allow the camera, and play. Desktop Chrome or Edge gives the smoothest results, and Safari is supported.
Is my camera video uploaded anywhere?
No. The hand model runs on your device, and the video never leaves your browser. Nothing is stored on a server.
Do I need to know music theory?
No. Held upright, all seven chords belong to the same key, so any order you play sounds musical. The chord names are shown on screen if you want to learn them.
Why does it play the wrong chord sometimes?
Usually a finger is only half raised, or the light is low. Spread your fingers clearly, face your palm to the camera, and try the Stable response setting.
I am left-handed. Can I switch hands?
Yes. Turn on Swap hands in settings, and your right hand picks chords while your left hand controls volume, tone and voicing.
What if my camera is blocked or missing?
You can still play with keys 1 to 7 or the on-screen pads. If you blocked the camera by accident, the page shows steps for Chrome, Edge and Safari to allow it again.
Does it work on a phone?
Yes, though it is less smooth than on a computer. Turn the phone sideways so both hands fit in the picture, or use the touch pads.
Is this the same as the gesture synth trend on TikTok?
Gestune is an independent instrument built around the same idea: making music with your hands in front of a camera. It includes songs to learn, a theremin mode and clip recording.