Make music with your Claude subscription

Bring out the musical talent you didn’t know you had.

Download for macOSView on GitHub

macOS 11+ · Apple silicon · MIT license

What you can do

Start from scratch, or arrange a MIDI from the web. It’s up to you.

Ask Claude for a brand-new piece, or open a MIDI file you found online and arrange it together. When it’s ready, print it as a score or practice it on the piano roll.

Start a new piece from nothing

Ask for “an 8-bar lo-fi piano piece” or “a string quartet in D minor” and Claude writes it bar by bar. Then ask for more: a bass line for bars 9–16, a new ending, a more legato melody.

Working with Claude

Say “this bar” and Claude knows which one.

Claude reads the song you have open and works on the bars you point at.

  • Point at the music

    Drag a range on the piano roll and attach it to the chat. “Here”, “this part” and “this register” then mean exactly that.

  • Starts from real scores

    Ask for an existing piece and Claude finds a public-domain score on IMSLP, Mutopia or Wikimedia Commons, imports it, and tells you where it came from.

  • You approve every edit

    Claude’s changes are staged, never written straight into your song. Keep them, throw them away, or undo them later like any other edit.

  • Notes only

    Otomo writes notation and MIDI. It doesn’t generate audio, and the scores and MIDI you make belong to you.

Playback

Hear your music at its best.

Otomo has its own playback engine, written in Rust. It plays each track on a sampled instrument, adds the reverb of a real room, and on headphones places the players around you.

ReverbMost MIDI players have none, which is why they sound flat. Choose a room by how long it rings, and sit further back to hear more of it.
  • No reverb0 s
  • Recording studio0.4 s
  • Live club0.65 s
  • Chamber music hall1.5 s
  • Concert hall2.0 s
  • Cathedral4.8 s
Instruments
Salamander Grand PianoVS Chamber Orchestra 2 CEFreePatsKaroryferYour own SFZAudioUnit instruments
Each free library downloads in one click, and every track gets a fitting instrument.
Listen A/B · with and without the room
The same notes in a large concert hall, heard from the middle0:00 / –:––

Audio clip coming soon

Without Claude, too

A capable MIDI and score tool on its own.

  • Piano roll

    With chords, lyrics, pitch bend and controller lanes.

  • Score

    Engraved notation, ready to print or hand to players.

  • Event list

    Every event, down to SysEx, when you need the detail.

  • Opens MIDI and MusicXML (.musicxml, .xml, .mxl)
  • Drop files anywhere to add them to your library
  • Copy bars between songs, paste with transposition
  • PDF full score or parts, at written pitch
  • MusicXML for MuseScore, Dorico, Sibelius and Finale
  • English and Japanese, light and dark

Connect Claude

Use the Claude you already have.

Otomo has no account or server of its own. It plays and shows scores without Claude; to compose and edit, connect the Claude you use, in either or both of two ways.

In-app chat

A chat panel next to your score

  1. 1Install Claude Code and sign in.
  2. 2Press ⌘L in Otomo.

Pick the model and effort. It runs on your own Claude Code login and needs macOS 13+.

Claude Desktop

Otomo’s tools inside Claude

  1. 1Click Connect to Claude in Otomo.
  2. 2Restart Claude Desktop.

Edits arrive in Otomo the same way, as pending edits. Your other MCP servers are left alone.

Every write lands in the pending-edits queue. See the MCP tools Claude gets

Open source.

Otomo is MIT licensed, has no account or server of its own, and the scores and MIDI you make are yours.

Download for macOSStar on GitHub

Apple silicon (M1 or later) · macOS 11+ · In-app chat needs macOS 13+