I'm not getting any sound in Linux. Can you tell me how OHRRPGCE outputs MIDI so that I can set up my system correctly?

The GNU/Linux version of the OHRRPGCE uses SDL_Mixer, which in turn uses an embedded ancient version of Timidity to play MIDI (and BAM). See Linux Notes for details about getting MIDI to work.

Make sure that you have both packages installed. If SDL_mixer is missing, the program will not even run, but if instruments for Timidity are missing, it will run, but only play sound effects music and music other than MIDI and BAM.