A playable grid of notes where every interval has the same shape wherever you play it. Choose an 8×8 square grid or a 61-key hexagonal one, play it with the mouse, touch or a controller, and watch which notes and chords you use light up as you go. It sends MIDI; connect it to an instrument to hear it.
The idea
On a piano, a major chord looks different in every key. On an isomorphic layout, moving one cell to the right always adds the same interval, and so does moving up. Learn a chord or a scale shape once and it works from any starting note: shift it across the grid and it transposes.
Two numbers define a layout: the Column interval (one step to the right) and the Row interval (one step up, or up-right on the hexagonal grid), in semitones. The hexagonal grid has a third direction, up-left, which always equals the row interval minus the column interval; the face shows and edits all three while keeping them consistent. The Base note sits in the lower-left cell. A note can appear in several places at once, and every copy lights up together.
Layouts
The presets cover well-known layouts: Aura and Aura Reverse (square grids), Exquis (hexagonal: right +1, up-right +4, up-left +3 semitones), Chromatic Fourths, Chromatic, Fifths, Harmonic Table, Wicki-Hayden, Jankó, Guitar Fourths and Tritone Rows. The shortcut strip above the grid, or Alt+1–9 with the face focused, switches the layout while keeping your base note, transposition and history.
These presets reproduce each layout's interval rule. They are not full emulations of the hardware controllers that use them, with their own key numbering, colours and expression.
Playing and listening
- Play the grid with the pointer or touch, or with Space/Enter on a focused key. Transpose shifts everything by up to four octaves.
- Input chooses how incoming MIDI is read. MIDI notes shows the notes any keyboard or sequencer plays and passes them on, transposed. Grid positions treats incoming note numbers as cell numbers, for a pad controller that should play the grid's own layout.
- Sounding lists the notes currently playing and their intervals above the bass, and Possible chord names them, with alternative readings for inversions and ambiguous sets.
- Display switches the grid between live notes and two heatmaps that fade over History half-life: how often each note started, or how long it sounded. Fold octaves combines all octaves of a note. Clear history starts over.
- Recent onsets and Melody path show your last notes in order, drawn as a path on the grid.
- Pin shape keeps up to eight chords or shapes for comparison, overlaid on the live grid. Hold to audition pin plays a pinned shape back, and Keep / Leave / Arrive shows which notes stay, go and appear between it and what you are playing now.
- Scale root and Scale overlay dim notes outside a chosen scale and label scale degrees. The overlay only guides the eye: every key stays playable and the MIDI is never filtered.
- Fit sounding notes moves the base note so the grid contains as many of the notes you are playing as possible.
Getting started
Connect the MIDI output to any instrument, pick Exquis or Aura, and play a major triad. Then play the same shape from another cell. To analyse what you play elsewhere, send a keyboard or sequencer into the MIDI input and set Display to a heatmap.
Limits
The keyboard handles note on and off only. Sustain, pitch bend, controllers and program changes are not passed through. History and pins are part of the session and start empty next time; the layout settings are saved.
