Whose Hand is on the Vinyl? Transcribing a DJ's Scratch Gestures from Video into a Playable Instrument

A scratch is not a sound but a pair of coordinated motions: how the record was turned, and how the crossfader gated the result. "Whose Hand is on the Vinyl?" recovers both curves from overhead recordings of scratch performances by computer vision, with no network trained and none run, and ships them as an Audio Unit / VST3 instrument in which each MIDI note re-executes one recorded gesture on the player's own sample, checkable against the frames it came from. The work asks where creative agency sits once a bodily skill becomes a file anyone can trigger.