MP3 to MIDI: check note timing before you set the project tempo.
The exported MIDI carries note positions from the detector run; it does not automatically choose the right DAW tempo for your song. Compare the note windows with the source before quantizing or stretching the project.
Use the recorded timing windows
The public results.json records each event's start and end values for the site's four-note source.mp3. Those windows are the evidence to inspect before changing tempo.
| Step | Check | Do not assume |
|---|---|---|
| Compare | Line up MIDI note starts with the source | That a default project BPM matches the recording |
| Set | Choose a tempo that fits the source performance | That quantizing preserves the original feel |
| Edit | Correct timing drift manually when needed | That every detected boundary is musically final |
What this test can and cannot say
The controlled fixture establishes note events and timing windows for an isolated melody. It does not establish full-song tempo tracking, groove preservation, or a universal quantization setting for mixed audio.
After timing is checked
Import the MIDI into your DAW, compare the piano roll with the MP3, and only then decide whether to quantize, stretch, or leave the performance free-time. Keep the source and MIDI together while making that decision.
Questions about tempo
Does MP3 to MIDI detect the song BPM?
This evidence page does not claim a BPM result. It records note timing windows, which you can compare with the source before setting a project tempo.
Should I quantize immediately?
No. Check the source alignment first; quantization can change the performed feel.
What if timing drifts across a full song?
Treat it as a separate full-song check. The isolated melody fixture does not establish long-form tempo tracking.