Unexpected dynamic behavior when combining sf with a decrescendo hairpin

Issue type

General playback bug

Description with steps to reproduce

Minimal Example:

1. Open a new blank score.
2. Enter 5 notes.
3. Attach ppp to the 1st note.
4. Attach sf to the 2nd and 5th notes.
5. Add a decrescendo hairpin from the 2nd to the 5th note.
6. Play back the score.

Expected Behavior:
The first note is very quiet, followed by an accented note, then two notes that gradually decrease in volume (arguably starting either from the sf the ppp level), and finally a closing accented note.

Actual Behavior:
The first note is very quiet, followed by an accented note, then a very quiet note, a loud note, and finally a closing accented note.

Supporting files, videos and screenshots

More complex example (shown in the videos):

Expected Behavior (beats 2–5):
An accented note (relative to ppp), followed by a gradual decrease in volume (arguably starting from ppp or slightly above).

Actual Behavior:

Versions 4.4.3–4.7.4 (including 4.7 nightly):
https://github.com/user-attachments/assets/9c7bea3e-def1-4d2c-bc99-700dc1f54ca0

• The first note is accented much more strongly than expected.
• The second note plays at ppp.
• Playback becomes considerably louder from the third note onward (as if an sf were applied).
• The repeated section is played too loudly throughout.

Versions 4.4.0–4.4.2:
https://github.com/user-attachments/assets/b1f3b627-12b1-4f06-8a26-086930ac47ac

• The last measure behaves as in versions 4.4.3–4.7.4.
• Otherwise, playback is consistently too loud.

Up to version 4.3.2:
https://github.com/user-attachments/assets/ef3d3df4-12ad-4d2d-b683-ac5bba4f0951

• Playback is consistently too loud.

Version 5.0 (nightly main):
https://github.com/user-attachments/assets/294b5102-add1-4173-a8b8-e56302595266

• Playback is almost as expected, but the hairpins are interpreted as crescendos instead of decrescendos.

dynamic_test.zip

In which versions of MuseScore Studio is this issue present?

(4.4.0) 4.4.3 - 4.7.4

Regression

No.

Operating system

Windows 11 26200.8875

Additional context

Additional Information:
The playback behavior described occurs with MuseSounds, MS Basic, and external VST instruments, but it is not reflected in the exported MIDI file.
Small changes to the score (as shown at the end of the 4.7.4 video) can significantly alter the playback behavior.

Note:
The example file was created in version 4.4.0. The length of the last hairpin was adjusted (as is standard in versions 4.4.3 and later)—this adjustment triggers the unusual playback behavior in the last measure.

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