Chords.fm

Transcription Assistant

Free, browser-native tool for transcribing music by ear. Slow songs down without changing pitch, loop sections, transpose, isolate vocals — all in your browser, no upload required.

Keyboard shortcuts

  • Space — play / pause
  • — skip ±5 seconds
  • M — drop a marker at the playhead
About this tool

How accurate is it?

Tempo and pitch processing use Signalsmith Stretch — a phase-locked phase vocoder with formant preservation. Key + BPM detection runs through Essentia. Both are good on clean recordings and most pop / rock tracks; tempo detection can occasionally land on a half- or double-time multiple, and key may show a relative major / minor on ambiguous material. The slow-down + loop combination is what most musicians actually use this for — those are rock-solid.

Do you store the audio?

No. Everything runs in your browser — audio decoding, time-stretching, pitch-shifting, stem separation — and per-file state lives in your browser’s local storage. Nothing is uploaded.