How to get a clean result
- Record one thing at a time. A voice or one instrument, close to the microphone, in a quiet room. Reverb and backing tracks add notes that aren't there.
- Pick what is playing. Single line for a voice, whistle, horn or bass keeps one note at a time and the pitch bends. Chords for piano or guitar lets notes overlap.
- Listen to both. Play the recording and the notes together. Too many short notes? Lower the sensitivity or raise the shortest note. Quiet notes missing? Raise the sensitivity.
- Set the tempo before you download if you played to a click, and snap to the grid you want. The notes then line up with the bars in your DAW.
What is in the MIDI file
One track on channel 1 with the tempo you set, a 4/4 time signature, every note with a velocity taken from how loud it was, and pitch bends where the performance slid or drifted. The file sets the pitch wheel range to ±2 semitones, the General MIDI default, so bends sound right on most synths.
To see the file byte by byte, open it in the MIDI file inspector.
Questions
Is my recording uploaded anywhere?
No. The note detector is downloaded to your browser once (about 2 MB) and runs there. Your audio never leaves your computer.
How does it work?
It uses Basic Pitch, a small neural network from Spotify's Audio Intelligence Lab. It looks at the sound about 86 times a second and says which of the 88 piano notes are sounding, where notes begin, and the exact pitch in between. This page turns that into notes, pitch bends and a MIDI file.
What kind of audio works best?
One instrument or one voice, recorded close and without much reverb or background noise. Piano, guitar, voice, whistling, flute, violin and bass all work well. A full band mix also gives notes, but expect extra and missing ones: drums and effects confuse it.
What is the difference between Single line and Chords?
Single line keeps one note at a time, which is right for a voice, a whistle, a horn or a bass line, and keeps the pitch bends. Chords lets notes overlap, for piano, guitar or several instruments. Both read the same analysis, so you can switch and compare instantly.
Why are there pitch bends in my file?
Voices and many instruments slide between notes and sing a little sharp or flat. The bends keep that, so the MIDI sounds like the performance. A MIDI channel has one pitch wheel, so in Chords mode bends are only written for notes that sound alone. Turn bends off for a clean, quantised part.
Can it find the tempo?
Not yet. The notes keep their real timing. Set the tempo you played at and choose a grid to snap to, and the notes will line up with bars in your DAW.
Which audio formats can I open?
Anything your browser can play: MP3, WAV, M4A/AAC, FLAC and OGG in most browsers. Up to 5 minutes are converted at a time.
Note detection by Basic Pitch, © 2022 Spotify AB, Apache License 2.0.