MP3 to MIDI: check pitch and timing before you assume velocity.
The site's reproducible fixture records note events, pitches, and start/end windows; it does not establish a velocity claim. That distinction matters when a converter page says “MIDI output” but the next production step depends on expressive dynamics or separate instrument tracks.
What the public record contains
Open results.json beside the downloadable source.mp3. The controlled run uses the site's four-note melody, decodes to mono 11025 Hz PCM, and records event count, pitch, start, and end values for the generated MIDI.
| Output field | Evidence status | How to use it |
|---|---|---|
| Pitch | Recorded for each detected event | Compare the sequence with the source melody |
| Timing | Recorded as start and end windows | Check note placement before arranging |
| Velocity | Not established by this fixture record | Inspect the exported MIDI in your editor |
| Separate instrument tracks | Not established by this single-line detector | Do not infer multitrack separation from one MIDI file |
Why the distinction is useful
Recent audio-to-MIDI pages from competitors frame multi-instrument separation and preserved timing/velocity as product capabilities. This page takes the narrower, reproducible route: it tells you exactly which fields the local evidence records and where the evidence stops. A pitch-and-timing match is not a measured velocity result.
Post-export check
Download the generated MIDI, open it in a MIDI editor, and inspect velocity and track structure there. Keep the source recording beside the piano roll. If the passage contains chords, drums, or a full mix, treat those conditions as untested by this isolated melody fixture.
Questions about MIDI output
Does this evidence prove velocity was preserved?
No. The public record establishes pitch and timing windows, not a velocity comparison.
Does one MIDI file mean the instruments were separated?
No. This controlled detector run is a single-line melody check, so it does not establish multitrack separation.
What should I verify after download?
Check pitch, timing, velocity, and track layout in your MIDI editor. Keep the original MP3 beside the export while reviewing.