MP3 to MIDI: test the file before you trust the MIDI.
Yes, this MP3 to MIDI workflow produced a downloadable MIDI file from a real MP3 input. In the controlled test below, the encoded MP3 returned four note events; a silent MP3 returned zero events. Use the result as editable note data, then check it against the source before arranging.
What the other tools leave implicit
Jukeblocks explains that MP3 or WAV uploads can produce a Standard MIDI file and that simple recordings work better than dense mixes. AI-MIDI describes preview, instrument selection and download limits. Neither public page shows a downloadable input, a decoded file, event count, and a failure sample together. This page records those artifacts so the claim can be reproduced.
Real MP3 experiment
I started with a known four-note PCM melody (MIDI pitches 62, 65, 69 and 74), encoded it to a 128 kbps MP3 with FFmpeg 9.0.2, decoded that MP3 to mono 11,025 Hz PCM, and ran the deployed Note Foundry detector and MIDI writer on the decoded samples.
| Input | Output | Observed events |
|---|---|---|
| source.mp3 (128 kbps) | output.mid | 4: pitches 62, 65, 69, 74 |
| silent.mp3 | silent-output.mid | 0; detector reported “No clear notes found” |
The decoded MP3 notes started at about 0.180, 0.878, 1.576 and 2.275 seconds and ended at about 0.758, 1.457, 2.155 and 2.854 seconds. Those are detector outputs, not a promise of exact timing for every recording.
Reproduce it
- Download source.mp3 and silent.mp3.
- Run FFmpeg to decode each to mono PCM at 11,025 Hz.
- Run run-mp3-experiment.cjs with the deployed app.js.
- Compare the generated MIDI files with results.json.
This is a controlled isolated-melody test, not a full-song accuracy score. Chords, noise, speech, clipping and dense mixes need separate checks.
MP3 to MIDI questions
Will every MP3 produce notes?
No. The silent MP3 in this test produced zero events, so a valid file can still contain no detectable melody.
Can I download the MIDI?
Yes. The converter creates a Standard MIDI download; inspect it against the source before using it in a DAW.
Is MP3 as clean as WAV?
No. MP3 is compressed. If you have a clean WAV, compare both inputs and keep the one whose note events match the source more closely.