Built-in synth. Load an .sf2 soundfont for a sampled piano (session only).

Pick a layout — the song re-maps to it and plays. Or tap CUSTOMIZE MAP to remap keys yourself. Standard = two hands; Keyboard Game = a wide two-octave right hand.

Each note map is a fixed hand shape this song uses. Tap a map to jump your hand to it, then CUSTOMIZE MAP (or ↺ to reset that map) to change which note each key plays.

When the auto-chart doesn't feel good, this is where you'll fix it. Notes carry durations; each note map is computer-key → note; the schedule is which map to be on when.