Reproducible conversion test

Change MP3 to MIDI: download a known test and reproduce the result

Download one clean, known MP3 melody, change it to MIDI in the browser, and compare your result with the actual MIDI output below. This fixture produced 8 detected events from 8 designed tones: an event-count agreement of 100% for this specific test.

Known MP3 test audio with eight tones is converted to actual MIDI output with eight detected note events, yielding 100 percent event-count agreement for this fixture.
The number is deliberately narrow: it checks event count for one public fixture, not general transcription accuracy.
Short answer: download the known MP3 and its actual MIDI output, then run the MP3 through the browser converter. The test has eight isolated tones. The recorded result has eight MIDI events, so 8 detected / 8 designed = 100% event-count agreement for this fixture only.
Download known-input MP3Download actual MIDI output

What you are downloading

The input is a mono 192 kbps MP3, 5.85 seconds long. It contains eight 0.60-second pure-tone notes with seven 0.15-second silent gaps. The intended note sequence is C4 E4 G4 G4 E4 D4 C4 C4. It contains no drums, chords, reverb, vocal consonants, backing parts, or competing pitches.

The MIDI download is not hand-authored reference notation. It is the actual file written by the browser converter after processing this exact MP3 in Melody / solo instrument mode. The file is a Standard MIDI file with 8 detected events and is 110 bytes on the recorded run.

How to repeat the check

  1. Download the known-input MP3 above. Do not edit or re-encode it.
  2. Open the MP3 to MIDI tool, choose the file, leave the mode on Melody / solo instrument, and select Convert to MIDI.
  3. Read the displayed detected-note count, then download the result.
  4. Open your MIDI file in an editor and compare the count and broad order with the supplied actual output.

The reproducible number

Event-count agreement is 100%: 8 detected events / 8 designed tone events x 100 = 100%. The converter displayed eight events at approximately 0.00, 0.72, 1.49, 2.23, 2.97, 3.74, 4.48, 5.22 seconds. The source note starts are designed at 0.00, 0.75, 1.50, 2.25, 3.00, 3.75, 4.50, 5.25 seconds; the small differences reflect frame-based analysis and MP3 decoding.

This number is intentionally not an accuracy score for arbitrary music. It says only that the converter wrote the same number of events as this clean fixture contains. A full song, chord progression, drum loop, or reverberant vocal can produce a different result because this tool estimates one dominant melody.

Fixture propertyRecorded valueHow to check it
Input formatMono MP3, 192 kbpsDownload the linked input file and inspect it in an audio editor
Source duration5.85 secondsRead the file duration in an audio editor or media inspector
Designed tones8Count the listed note sequence
Recorded detected events8Run the converter and read its detected-note count
Actual output size110 bytesDownload the linked MIDI and inspect its file properties

What to compare beyond the count

A matching count is the first check, not the whole decision. Open the MIDI in a DAW or editor and confirm that it begins on C, rises to E then G, keeps the repeated G, returns through E and D, and ends with repeated C. That broad contour is more useful than treating every millisecond of timing as a pass/fail test.

For your own MP3, keep the same discipline. Choose a short exposed melody, compare the first note, main movement, repeat, and pause, then keep the MIDI only if those reference points agree. For editing guidance, use the MIDI cleanup workflow.

Where this test stops

This public test is a fixture, not a promise. It does not establish performance on full songs or multiple instruments, and it does not claim chord recognition, stem separation, drum transcription, or multitrack MIDI export. If a real MP3 contains competing pitches, choose a clearer phrase rather than expecting the fixture result to transfer unchanged.

Related: MP3 to MIDI converter pre-check · audio-to-MIDI result check · open a MIDI file