It's a problem with MIDI playback and some hardware, not all. Timidity fixes it because that makes prboom use software MIDI playback rather than hardware. It shouldn't be a dependency because not all hardware MIDI is affected.
I think it's a bug in the SDL mixer library.
You can get around it by either touching /etc/timidity/timidity.cfg or running with -nomusic (which still gives you sound effects).
It's a problem with MIDI playback and some hardware, not all. Timidity fixes it because that makes prboom use software MIDI playback rather than hardware. It shouldn't be a dependency because not all hardware MIDI is affected.
I think it's a bug in the SDL mixer library.
You can get around it by either touching /etc/timidity/ timidity. cfg or running with -nomusic (which still gives you sound effects).