Murmur — Catch the Tune in Your Head
murmur is a place to hum. Catch the tune in your head before it slips away, then turn those rough recordings into loops, MIDI and song sketches — all in the browser.
Features
- One-tap capture with latching or hold-to-record modes, an optional click and count-in, and tap tempo.
- Pitch detection turns a hummed melody into MIDI notes you can edit in a piano roll, and play back through a built-in synth or sampler.
- Tempo detection and time-stretching to “loopify” a clip onto a bar grid, with snapping to the clip’s or the song’s tempo.
- Arrange clips into songs on a clip grid with scenes and a song chain, then mix with per-track volume, mute and solo.
- Export audio (WAV) and MIDI files, or a whole project. A library groups clips by song and shows how much storage each one uses; the app asks the browser for persistent storage so recordings aren’t evicted.
- Vanilla JavaScript, the Web Audio API and AudioWorklets, installable as a full-screen web app that works offline.
Built with AI
This app was built with AI. I made it together with Claude, Anthropic’s AI assistant, using Claude Code, a tool that works directly in the terminal. I described the capture, pitch-detection, looping and mixing workflow I wanted. Claude wrote the code, and I directed the design, made the product decisions and tested everything in the browser. Commits that Claude wrote are marked as co-authored by Claude in the git history.