What this MIDI file contains
The local converter analyzes audio and writes detected pitch, start time, duration, and velocity into one MIDI track. It does not run a BPM detector, infer a time signature, or decide where measures begin. The Note sensitivity and Minimum note length controls change which note events survive; they do not set musical tempo.
Standard MIDI files can carry tempo and time-signature information. The MIDI Association's Standard MIDI Files page identifies both as supported file data. When a file has no tempo event, the Standard MIDI File default is 120 quarter notes per minute; software can still apply its own import behavior.
What we measured in a local export
We converted a self-generated four-second WAV containing one second each of A4, C5, E5, and G5 with the site's default controls. The exported draft contained five note events because A4 was split into a long event and a short edge fragment. Its resolution was 480 ticks per quarter note, and it contained no tempo events and no time-signature events.
| Detected event | Start | Duration |
|---|---|---|
| A4 | 0.023 s | 0.905 s |
| A4 edge fragment | 0.929 s | 0.070 s |
| C5 | 0.999 s | 0.989 s |
| E5 | 1.986 s | 1.010 s |
| G5 | 3.020 s | 0.952 s |
The final detected note ended at 3.972 seconds. These measurements show that this test draft retained useful event positions, but they do not prove accuracy for other recordings or supply a musical beat grid.
How to align the draft in a DAW
- Keep a reference. Import the local audio you are authorized to use on an audio track and the MIDI draft on a MIDI track.
- Choose a clear first attack. Move the MIDI region so that attack matches the audio. Do not assume the first detected event is exactly at the start of a bar.
- Set the project tempo. If the recording is steady, enter its known BPM or use your DAW's tempo-detection tool. If it speeds up or slows down, create a tempo map instead of forcing one value.
- Check later landmarks. Compare several attacks near the middle and end. A start that matches while later notes drift usually points to a tempo-grid mismatch.
- Quantize selectively. Use a sensible grid and strength, then listen against the source. Full-strength quantization can remove intentional timing.
When to return to the converter controls
Return to the converter if the draft has missing notes, duplicate fragments, or events too short to edit comfortably. Those are detection problems. A whole performance that stays internally spaced but misses bar lines is a DAW tempo and alignment problem. For measured cleanup steps, use the extra-note guide; for an empty result, use the no-notes guide.
Why the source may never fit one BPM
Live performances can breathe, slow down, or speed up. Video edits can also join passages recorded at different times. In those cases there is no single BPM that makes every attack land on a fixed grid. Preserve the event timing, build a tempo map from musical landmarks, and edit notes only after the map follows the performance.