Damper

Piano audio to MIDI

Upload a solo-piano recording. Get back one editable MIDI file containing the notes, their timing, how hard each was struck, and the movement of the sustain pedal.

What you actually receive

A single standard MIDI file, type 0, one track. It opens in any DAW or notation editor. Inside it there are four things, and it is worth knowing which are measured and which are reconstructed:

Pitch and onsetsDetected from the recording. Never altered afterwards.
Note lengthsRebuilt. A pianist's finger usually leaves the key long before the sound stops — the pedal is holding it.
VelocityMapped onto a curve calibrated against hundreds of hand-corrected notes, so the file plays musically straight away.
Sustain pedal (CC64)Reconstructed from the harmony heard in the audio, then placed on an exact note onset.

How it works

  1. The notes come first. A transcription model trained on real piano recordings finds every pitch and the instant it was struck.
  2. Then the harmony is listened to. A five-model ensemble follows the chord and the bass through the recording. This is what decides where the pedal moves — not a rule about beats or bar lines.
  3. Then the pedal is placed on a real onset. A harmonic change alone is not enough: the pedal only moves where an actual note is struck. A low arpeggiated bass therefore does not generate four pedal changes.
  4. Lengths and velocity last. Notes get a short key-down by default; only the top voice and a few fingers genuinely held at a pedal lift keep their long duration.

What it handles

Any audio or video file your browser can send — MP3, WAV, FLAC, M4A, OGG, or the audio track of a video. Everything is converted before processing, so the container does not matter. Up to 15 minutes per file. A four-minute piece takes about two minutes.

What it does not do

How accurate the pedal is

On the reference set used to calibrate it — ten pieces pedalled by hand, 433 pedal events — roughly three changes out of four land within a sixteenth of a beat. That is a real measurement on a specific set, not a general guarantee: recordings with heavy reverb, or a piano very unlike the calibration material, will do worse. The pedal in your file is a strong starting point that repays a read-through, not a finished performance.

Transcribe a recording