So... The problem with this particular game is that it will try to play the music through the FM synth hardware, if it detects that it is present in the hardware. Since CrabEmu's core does have support for emulating the YM2413 FM synth, the detection code determines (incorrectly on the Dreamcast) that it is present and thus it tries to play all sounds through that, instead of through the PSG.
The optimal solution would be to work on getting the YM2413 synth supported on the Dreamcast version. Unfortunately, this piece of code is exceedingly slow, and ends up pushing the framerate down unacceptably on the Dreamcast version. So, a stopgap solution would be to make sure that on the Dreamcast version, the FM synth isn't (incorrectly) detected as present (and likewise so that it isn't detected as present when it is disabled on the OS X version). That's what I'll start with in fixing this bug, at least.
The issue should be resolved in r230, which I just committed moments ago.
Closing as fixed.