Open a MIDI file and edit it as notes on a piano roll: fix a wrong note, move a part up an octave, tighten the timing, change the instrument, and save it again. Start from New to write a part from scratch.
Editing on the roll
Time runs left to right with the bar numbers in the ruler, and pitch bottom to top with every C marked on the keyboard at the left.
| Action | Does |
|---|---|
| Click empty space | draws a note one grid step long; keep dragging to stretch it |
| Drag a note | moves it, and the whole selection with it, in time and pitch |
| Drag a note’s right edge | changes its length |
| Double-click a note | deletes it |
| Shift-click | adds to or removes from the selection |
| Shift-drag on empty space | selects everything in the box |
| Click the ruler | moves the play cursor |
| Click the keyboard | plays that pitch |
With the roll focused, the keyboard does the rest:
| Keys | Does |
|---|---|
| Delete or Backspace | deletes the selection |
| Arrow up / down | transposes a semitone; with Shift, an octave |
| Arrow left / right | nudges one grid step |
| Ctrl+D | duplicates the selection right after itself |
| Ctrl+A | selects every note |
| Ctrl+Z, Ctrl+Shift+Z | undo, redo |
| Space | plays from the cursor, or stops |
Every edit can be undone, back 200 steps. A slider dragged from one end to the other is a single step.
Snap, quantize, and tempo
Snap sets the grid that drawing, moving, and stretching follow, from a beat down to a 1/32 note, with an eighth-note triplet grid for swung parts. Turn it off to place notes freely.
Quantize moves the start of every selected note to the nearest grid line and keeps its length, or quantizes the whole song when nothing is selected. It is the quickest way to tidy a part played in by hand or one that came from Audio to MIDI.
The tempo slider works the way a DAW’s does: the notes stay on their beats, so the song gets faster or slower. The tempo is written into the saved file.
Channels and instruments
Notes on the channel you are drawing on are shown in the tool’s colour, with brighter notes for higher velocity. The other channels are drawn quieter, so a busy arrangement stays readable while you work on one part. Instrument changes the channel’s General MIDI family, from Piano and Organ to Synth pad and Sound effects, and the saved file names that family’s first program, so a General MIDI player or a DAW loads a matching sound.
Saving
Download MIDI writes a format 0 Standard MIDI File: one track holding every channel, with a program change per channel and the tempo. Download WAV renders the song through the built-in synthesiser, the same one MIDI to Audio uses, with muted channels left out.
The editor keeps notes, not events, so anything that is not a note is dropped on save: sustain pedal and other controllers, pitch bend, program changes partway through, lyrics, and tempo changes after the first. For a file that depends on those, edit in a DAW.