Melrōse is a command-line music tool that lets you write melody expressions, loop them, and play them through MIDI devices. The repo also includes a custom DSL, playback and timing logic, and a MIDI server entry point.
People who want to write melodies in code and hear them through MIDI devices.
You can edit musical patterns while they are playing and hear the changes immediately.
Lets you describe note sequences, scales, chords, loops, and tracks in a small DSL.
Updates note sequences while playback is running for immediate audible feedback.
Sends programmed music to MIDI output devices and MIDI files.
Provides `melrose`, `melrose_midi`, and a VS Code-related command under `cmd/`.
Includes a Melrōse MCP server mentioned in the README for receiving expressions to play.
melrōse is a tool to create and play music by programming melodies.
It uses a custom language to compose notes and create loops and tracks to play.
This is an example of a simple major scale C.
sequence('c d e f g a b c5')
Note sequences in your program can be changed while playing giving you direct audible feedback.
For the best experience, use the melrōse tool together with the Visual Studio Code Plugin for Melrōse.
See also Blog post
See Melrōse Playground to start writing programs directly in the browser and connect to a local running MIDI receiver, e.g. Apple Garageband.
To have a full experience of the tool in which you can work with multiple devices and files, you can install it locally on our machine. See Build instructions.
melrōse is a tool to create music by programming melodies and uses a custom language to compose notes that are played with MIDI.
Note sequences in your program can be changed while playing which makes it possible to even use it for live performance.
For the best experience, use the melrōse together with the Visual Studio Code Plugin for Melrōse.
Read the documentation on how to use melrōse.
The language has reached version 1.0 since tool version v1.0.0 and therefore future changes will only extend it (1.x) and not introduce breaking changes.
melrose-mcp is a (server) tool that uses the MCP protocol to receive expressions to play.
See melrose-mcp for details how to install and use it.
Fixes, suggestions, documentation improvements are all welcome. Fork this project and submit small Pull requests. Discuss larger ones in the Issues list. You can also sponsor Melrōse via Github Sponsors.
Software is licensed under MIT. © 2026 ernestmicklei.com
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