About Composer Sketch

Composer Sketch is a free song sketchbook that runs in your web browser. Catch an idea on your phone on the way to school or work — a beat, a bass line, a chord loop, a melody — and finish it later at home: export it as a MIDI file and open it in the full music program you use, or render it to a WAV file to listen to anywhere.

What you can do

• Key and scale — pick a root and a scale (minor, major, harmonic minor, dorian, phrygian, pentatonics). With scale lock on, only notes of the key are shown, so every note fits.
• Piano roll — tap to add a note, tap it again to delete, drag to move, drag its right end to resize. Chord modes place a 3- or 4-note chord in one tap.
• Chord progressions — fill a track with a ready-made progression in the current key: pop, emotional pop, K-pop, R&B, EDM anthem, dark trap, drill and lo-fi.
• Instruments — 808 bass with glide, keys, pad, pluck and lead, plus drums (kick, snare, clap, hi-hats, perc) with 2-, 3- and 4-hit rolls.
• Mixer — volume, pan, tone, reverb and a tempo-synced delay on every track, with mute, solo and a sidechain-style pump.
• Sections and song — make sections such as Intro, Verse, Chorus and Drop, then chain them with repeat counts into a song.
• Keyboard input — play with a USB or Bluetooth MIDI keyboard (Chrome and Edge) or the computer keys, and record into a track.
• Export — a standard MIDI file (one track per instrument, drums on the General MIDI map) for any music or notation program, a WAV file of the song or section, and a project file you can open again here.

From phone to studio

1. Sketch the idea on your phone. Your current project stays in the browser, so you can close the page and come back.
2. Tap Save to keep a project file, or Export MIDI to get the notes.
3. At home, open the MIDI file in your music program: each instrument arrives as its own track with the tempo and key already set, ready for real sounds and mixing.

How it works

Every sound is generated with the browser's Web Audio API, and WAV and MIDI files are made on your device. The site ships no sample library and has no server-side processing: nothing you make leaves your browser.

Principles

• No uploads. Nothing you make is sent to us.
• No sign-up, no payment. Every feature is free; the site is funded by advertising.
• Installable. Add it to your home screen to use it full-screen like an app.

Contact

Found a bug or have an idea? Write to deeprealx@gmail.com. Please mention your device and browser.