It's not that it's not good enough, but Windows 98 wasn't designed to run DOS games and not all DOS games will run properly in 98 either. While some could, there were often sound/music problems. Some would refuse to run at all (Crusader: No Remorse & Crusader: No Regret being two games I loved that lost playability in Windows 98).
The reason you're getting music and no sound effects is because the music is straight CD audio playing off the CD (according to what I've read about that game). In Windows 98, CD audio was passed through an audio cable straight to the sound card and out through the speakers. Even if a Windows 98 (or previous version of Windows or DOS) computer locked up, CD audio would still continue uninterrupted.
This is no longer the case with most newer computers, as CD audio is dealt with differently now.