Pocket Composer

A four-track step sequencer with a piano-roll grid, a transport, track mute controls and a visible playhead. The grid keeps musical position, pitch and active notes together.

Run it

Build the examples with devenv shell -- lcom-ng-build, then run:

lcom-ng run -- build/examples/music_maker build/pattern.mlpat

Try a complete workflow

Toggle notes with the mouse or Enter, move with arrows, and press Space to listen. Adjust tempo and track mutes, undo an edit, then save the pattern and reopen it in a later run.

Controls

Control	Action
Space / P	Play or pause
Click / arrows + Enter	Write or toggle a note
1-4 / Tab	Select instrument
M / track M button	Mute selected track
- / + or transport buttons	Change tempo
Backspace / Delete	Remove current note
C / R	Clear track / restore demo pattern
Cmd/Ctrl+S / S / F2	Save pattern
Cmd/Ctrl+Z / Shift+Z	Undo / redo
F1	Shortcuts

Command shortcuts work on macOS; Ctrl shortcuts work on other hosts. Esc closes help first. Cmd/Ctrl+W closes the app.

In the app

These are actual runtime captures. Open a screenshot for a larger view; use Left and Right to browse, and Escape to close.

One loop, four voicesThe piano roll separates the active voice from the other tracks, with a compact pattern overview below.

Shape the bass lineNumber keys select instruments and the lane overview exposes every track.

A rhythm of its ownThe drum lane can be edited with the same mouse and keyboard controls as melodic voices.

Hear the whole loopSpace starts real AC97 audio playback with a visible step playhead.

Make room in the mixMute is visible on each instrument and changes the audio that is actually rendered.

Start a new partClear removes only the selected instrument; Undo restores the previous pattern.

Keep the compositionCommand-S saves a reloadable pattern including tempo and mute states.

The complete control mapThe modal help lists writing, transport, history, persistence and tempo controls.

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One loop, four voices · The piano roll separates the active voice from the other tracks, with a compact pattern overview below.

What it demonstrates

PIT timing, keyboard and mouse event handling, AC97 audio, reusable PCM buffers, note sequencing and pattern persistence.

The sound is synthesized locally. Pattern files store notes and tempo, rather than recorded audio.

Source: examples/music_maker.c.

Refresh these screenshots

devenv shell -- python3 scripts/capture_gallery.py --app music-maker

See the screenshot workflow to add states or check freshness.