simple hand tracking chords — play any song with chord gestures_
Play chords with your hands in the air
Allow the camera and your hands become 20 real chords — enough to strum along with most simple songs. Works best about an arm's length from the camera with a light source in front of you.
Chord chart 20 chords
Instrument 15 voices
Sound
Record
Tracking & display
Guide — how to play a song with hand gesture chords
Press Start camera and accept the browser prompt. The hand model downloads once (a few megabytes) and is then cached — the second visit starts almost instantly. Nothing is uploaded.
Look up any beginner songbook chart online. Almost every simple song leans on a handful of open chords — G, C, D, Em and Am cover a huge share of popular songs.
Check the Chord Chart panel on the right. Right hand = majors, left hand = minors, tilt the hand for the second row, pinch for 7ths.
Show the gesture for the first chord, hold it, then switch shape for the next chord in the song — in rhythm, the same way you'd change shapes on a guitar neck.
Flick your hand down to re-attack a held chord like a strum. Press ● Record to capture the take as video and a clean WAV.
The gesture system
Relaxed (not tilted, not pinching), show 1 to 5 fingers for C · G · D · A · E. Tilt the hand outward and show 1 or 2 fingers for F and Bb.
- 1 finger
- C
- 2 fingers
- G
- 3 fingers
- D
- 4 fingers
- A
- Open palm
- E
- Tilted · 1
- F
- Tilted · 2
- Bb
Same idea, mirrored: relaxed left hand, 1 to 5 fingers for Am · Em · Dm · Bm · F#m. Tilted with 1 finger gives Cm.
- 1 finger
- Am
- 2 fingers
- Em
- 3 fingers
- Dm
- 4 fingers
- Bm
- Open palm
- F#m
- Tilted · 1
- Cm
- Tilted · 2
- B7 (the odd one out)
Touch thumb to index finger — the same pinch Hand Tracking Instrument uses for sustain, repurposed here for dominant and minor 7ths.
- Right, pinch
- Slide left→right across the frame for C7 · G7 · D7 · A7 · E7
- Left, pinch
- Am7, anywhere in frame
These work at all times, for either hand.
- Fist ✊
- Silences that hand instantly
- Strum
- Quick downward flick re-attacks the held chord
- Hand height
- Volume — raise the hand to swell
- F
- Fullscreen performance mode
- R
- Start / stop recording
- Space
- Panic — silence everything
- [ ]
- Previous / next instrument
Each hand is tracked and voiced independently. For a normal song, follow the chart with one hand at a time — but both hands can hold different chords together if you want a richer, two-chord blend.
Watch the live chord name on the HUD. If it flickers between two chords, hold the shape a little steadier and make sure the whole hand — including fingertips — stays inside the frame with good light in front of you.
A chord instrument built to play real songs, not just demo gestures
Hand Tracking Instrument's Chord Conductor mode is powerful but abstract — the same hand shape plays a different chord depending on which key and scale you've dialled in, because it thinks in scale degrees. Simple Hand Tracking Chords throws that abstraction away. Every gesture here maps to one fixed, named chord — the same 20 chords a beginner guitarist learns first — so you can take a real song's chord chart from anywhere on the internet and play it directly, without translating roman numerals in your head.
The camera watches your hands, a landmark model returns twenty-one points per hand about thirty times a second, and those points are read for exactly four things: which hand it is, how many fingers are extended, whether the hand is tilted outward, and whether the thumb is pinched to the index finger. That's the entire gesture vocabulary, and it's enough to address all 20 chords with no overlap and no ambiguity.
Twenty chords, one gesture each
The right hand plays the seven major chords — C, G, D, A, E by finger count from one to five, then F and Bb by tilting the hand and showing one or two fingers. The left hand mirrors this for the six minor chords — Am, Em, Dm, Bm, F#m by finger count, then Cm tilted. That covers thirteen chords with a completely regular, learnable pattern. The remaining seven chords are dominant and minor 7ths: pinching the right hand and sliding it left to right across the frame steps through C7, G7, D7, A7 and E7, pinching the left hand anywhere gives Am7, and B7 — the one chord with no plain major sibling in this set — takes the one open slot left in the tilted-left-hand row.
Fifteen instruments, none of them samples
The synthesis engine is shared with Hand Tracking Instrument: nothing here is a recording. Every note is built live with the Web Audio API. Nylon Guitar and Concert Harp use Karplus-Strong synthesis — a genuine physical model of a plucked string. Electric Piano and Vibraphone are two-operator FM. Struck Piano and Music Box are additive with inharmonic partials. Warm Pad, Bowed Strings, Brass Section, Bright Lead and Retro Square are subtractive — detuned oscillator stacks through a filter envelope. Church Organ is a drawbar stack and Flute is filtered noise.
Built for playing along, not just messing about
A chord shape sustains for as long as you hold it, and a quick downward flick of the hand re-attacks it — a strum, without needing to change your finger count. Both hands are tracked and voiced independently, so a song is simply a matter of showing each gesture from the chart in turn, in time. Recording captures the canvas exactly as you see it — camera, hand skeleton and live chord names — as a WebM video with synth audio mixed in, plus a clean 16-bit WAV written straight from the audio bus.
Where the video goes: nowhere
The camera stream is handed to a canvas and a model running inside your browser tab. It is not sent to a server, because there is no server — the whole instrument is one HTML file. The only recording that ever exists is one you start deliberately, and it stays in your machine's memory until you download it or close the tab.