The on-screen keyboard
Every battuta action is a keystroke — which is a problem on a tablet. The on-screen keyboard puts the whole keymap on screen: toggle it with 🎹 in the header (touch devices show it automatically), close it with its ×. Leave it up and it comes back the next time you open battuta.
Under the × sits ⌫, always in reach: it erases backward like a text editor — the note before the caret becomes a rest and the caret steps onto it, so a wrong note is one tap away from gone. On a tablet or a phone held upright the panel takes two lines — octaves, piano, latches, × and ⌫ on the first, the action groups on the second — so the piano gets the width of the screen; turn it and it goes back to one line, keeping your octave and latches.
The piano
Section titled “The piano”Two octaves — one on a phone, where two would leave the keys too thin to play — playing into note entry exactly like a MIDI keyboard: in input mode a tap enters that pitch at its written octave (black keys enter sharps), and holding several keys builds a chord — with multi-touch, played like a real chord. The caret advances when the last finger lifts.
The rail on the left steps the visible octaves (▲ / ▼ around the low octave’s label); a wheel or two-finger scroll over the piano does the same.
Modifier latches
Section titled “Modifier latches”alt and shift are sticky: tap one and it applies to the next key, then releases — tap again to cancel. They behave like the real modifiers, so everything in the keyboard reference holds: latch shift and → extends the selection, latch alt and the arrows become shorten/lengthen duration. (There is no ctrl latch: every ctrl chord has a button of its own in the system group.)
While a latch is on, the keys relabel to what they will now do, the remapped ones are tinted, and the ones that latch reaches nothing on dim:
The digit pad
Section titled “The digit pad”One pad, four meanings — the latches choose:
| Latch | 1–5 | 6–0 |
|---|---|---|
| none | duration (7 = whole … 1 = 64th, in input mode) | — |
| shift | volta 1–5 toggle (block selection) | volta 6–9 |
| alt | fingering 1–5 (add shift too to stack) | finger change → 1–5 |
Everything else
Section titled “Everything else”The remaining groups mirror the keymap itself — the buttons are generated from your live bindings, so a rebound key or a brand-new action shows up on its own, and actions reached by a modifier (marcato = shifted accent, measure repeat = shifted simile…) appear when their latch is on rather than crowding the panel. The nav cluster is a D-pad (home/left, up/down, end/right, paging), and the system group carries save, open, undo/redo, copy/paste, zoom and the measure operations.