MIDI export produces incorrect note lengths and rhythms when the score contains grace notes #31385
Description
Issue type
Opening/saving issue
Description with steps to reproduce
- Create a new score.
- Add one or more grace notes to any note.
- Confirm that playback inside MuseScore behaves correctly.
- Export the score as a MIDI file.
- Observe that the MIDI playback exhibits incorrect note lengths and rhythmic positions.
Supporting files, videos and screenshots
Playback inside MuseScore is correct, but exporting to MIDI introduces multiple issues.
Some notes are stretched to unintended lengths.
Notes may be inserted at unintended positions, resulting in broken rhythms.
When grace notes are added to passages with short note values, unintended chords may appear in the exported MIDI.
test.zip
In which versions of MuseScore Studio is this issue present?
MuseScore Studio 4.6.4 64-bit
Regression
Yes, this used to work in MuseScore 3.x and now is broken
Operating system
Windows 11
Additional context
Similar issues have been reported on social media and user forums.
https://musescore.org/ja/node/369948
https://musescore.org/en/node/356412
Checklist
- This report follows the guidelines for reporting bugs and issues
- I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
- I have attached all requested files and information to this report
- I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible