Originally Posted by Shadowcat
Yep, it's all midi, but the particular sound card you had determined the instruments available and the overall quality of the music you could expect to get in response to that midi data. So presuming that the SB16 emulation is precise, the tunes won't sound nearly as good in SB16 mode as they will if you choose General Midi, as the latter was intended for rather more expensive hardware.
Now admittedly the SB16 music test sounds better than I remember -- I'm not sure if that's purely because the emulated SB16 is better than the real thing, or if it's just the better speakers, or if my memory is doing the real SB16 an injustice -- but the General Midi music still sounds rather richer to my ears.
The same goes for System Shock, and probably any other game you have that supported a General Midi option, btw.