midi-sink

midi-sink models a tray of water with ink floating on it. Every gesture is an exact, area-preserving transformation of the whole sheet — Aubrey Jaffer's mathematical marbling — so the rings stay crisp after a thousand strokes. Two modes. MARBLE MODE is the tray under your hands: tap for a drop, drag to comb, twist two fingers for a vortex, pinch to fold, draw with the Pencil and a wake follows the tip. Plug in a MIDI instrument and it plays into the same water: an MPE controller's strike, pressure, glide and slide become drop, feed, comb and hue; a wind controller draws a single calligraphic line; any keyboard plays drops on the circle of fifths. PLAY MODE turns the iPad into an MPE instrument. A pitch lattice — chromatic grid, Jankó or piano grid — sits under your fingers; every touch is a joystick (sideways bends in semitones, push to feed ink, pull back to stir). The Apple Pencil…