Turn a recording into MIDI
Audio in, notes out. Hum a line, record a guitar part, or hand it a finished mix — what comes back is MIDI you can edit, re-voice, or hand to a different instrument entirely.
Monophonic and polyphonic are different problems
A single line — one note at a time, one instrument — is the easy case, and the results are close to exact. Pitch is unambiguous, onsets are clear, and the main question is how aggressively to quantise.
Polyphonic audio is genuinely hard. A piano chord is several simultaneous pitches whose harmonics overlap; deciding whether you heard three notes or four is sometimes ambiguous even to a trained ear. Expect a good transcription that needs editing, not a perfect one.
A whole mix, not just one part
Handing a full arrangement to a single transcriber produces mush, because it tries to explain every source at once. The route that works is to separate first and transcribe each stem on its own, with a model suited to that instrument — drums are an onset problem, bass is a monophonic pitch problem, and they want different treatment.
That is why transcription here is per-stem rather than a single pass. A mix comes back as several MIDI tracks, one per instrument, rather than one track containing everything.
What you can do with the notes
MIDI is the format that keeps its options open. The same transcription can be re-rendered by any of the instruments the model knows, quantised or left rubato, transposed, or exported to a DAW session where you replace the sound entirely.
FAQ
How accurate is it?
A clean monophonic line transcribes close to exactly. Dense polyphony gives a usable starting point that needs editing. Anyone quoting a single accuracy number for "audio to MIDI" is averaging over problems of wildly different difficulty.
Does it detect tempo and key?
Yes — tempo, downbeats and chords are worked out as part of the same pass, so the MIDI lands on a grid rather than floating free.
Can it transcribe drums?
Yes, and it is treated as a separate problem from pitched transcription: what matters is which drum and exactly when, not what pitch.