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.
Since 2.0 the tray also sounds, and it can be read two ways.

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 S-Pen 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.

TWO MEDIA. Sumi is ink on washi paper. Anod reads the same water as an
electric discharge: every strike a spark, the charge glowing by how far it has
been stretched, the water drawing its own field lines. Switch between them
live — the sheet is kept.

PLAY MODE turns the tablet into an MPE instrument. Thirteen layouts: the
chromatic grid, Jankó and the piano grid; a trumpet and a trombone whose
partials sit under your fingers while three valve pads or a slide retune every
held note; the Wicki–Hayden button field, a fretboard in three tunings, and a
theremin that is the whole screen. Every touch is a joystick (sideways bends
in semitones, push to feed ink, pull back to stir). The S-Pen plays legato
across the keys with real pressure as velocity, its tail-stir deepens vibrato,
and its button is the sustain pedal. A floating strip carries pitch, mod, two
assignable wheels, sustain and a panic button. The stream goes out over
USB-MIDI (the tablet appears to any computer as a class-compliant MIDI
device), a virtual MIDI device for on-device apps, Bluetooth LE MIDI, and — new
— a MIDI network session over Wi-Fi that a Mac or a PC connects to, so any DAW
or synth records a standard MPE performance while the water paints it.

SOUND. The app plays what it draws. A sampler loads Decent Sampler libraries —
thousands of free instruments exist in that format; bring your own, or play
the bundled Dan Tranh zither at first launch. Suzu, the built-in synth, is the
same mathematics one octave down: oscillators that cannot drift, a bowed string
that sings under your pressure, a bell, a flute, a saxophone, a trumpet whose
lips follow your slide, and six patches fitted to sampled instruments. Or let
your DAW make the sound and keep the picture.

AND THE REST. Palettes you can edit, with colour-blind-safe presets. Presets
that carry a whole session between the tablet, the desktop and the web. A
prints ledger: every paper dip is kept and re-exports at any size, up to 8K.
Session replay: record a performance and play it back frame for frame — here,
on another device, or in the browser.

Made for MPE controllers — ROLI Piano and Seaboard, Expressive E Osmose — the
ROLI Airwave's gesture CCs, wind controllers (Roland Aerophone, Odisei Travel
Sax) and classic keyboards.

Free software (AGPL-3.0). Collects nothing.