If you have the patched version of X-Com, the ROLAND.CAT music file was not updated to the the new file format, and the old file causes X-Com v1.4 to choke. Seems to have been an oversight that was never officially corrected; I guess because GM was starting to take over by then. There's an unofficial patch here.

Thanks! The game sounds really good on the MT-32.

I'm a bit confused that the Wikipedia "list of MT-32 games" article lists X-Com / UFO as primarily an MT-32 games when the game's .MID filenames all start with "GM". I guess they rearranged them to be primarily for GM at some point?

Well, I guess you could say "primarily" because v1.2 only supported MT-32/LAPC-I synths, and GM support was added later in the v1.4 patch. Separate .MID files were not part of any DOS release, but the Win9X "Gold Edition" port did have them.

Interesting. Well I decided that, to me, the music sounds superior on MT-32 versus General MIDI in the Steam version. The X-Com soundtrack is pretty synthy (rather than orchestral), and the MT-32 does that really well.

The only place that GM might sound better is the piano sounds in the beginning of the intro soundtrack.