For anyone who uses D1X rebirth and D2X rebirth:
When I played Descent as a kid, the music in the game was the CD music, so that's the music I want to hear. I'm using DXX for the higher resolutions and because the sound stutters on Descent 1 for some reason.
Is there any way I can use the higher quality CD music with DXX, rather than the MIDI music? I know many prefer the MIDI music but the CD music is what I grew up with. The music is present and correct if I play using the gog.com shortcut, but after copying the relevant files into the DXX folders, I only have MIDI music.
Thanks all :)

If you have the original disc, try inserting it into the DVD/CD drive and set the game to play the music from the CD.

I had the same issue. I solved it using Daemon Tools Lite to mount the disk image. On my system, the disk image is in C:\Program Files (x86)\GOG.com\Descent and Descent 2\Descent 2\DESCENT_ii.inst and DESCENT_ii.gog. I think they are BIN/CUE files. At any rate, use Daemon Tools to mount DESCENT_ii.inst, the smaller file (make sure not to mount DESCENT_ii.gog). Then launch d2x-rebirth.exe and go to Options -> Sound Effects & Music and check the CD Music checkbox.

That's what worked for me. I couldn't find any way to do anything like this for Descent 1 yet, though.

Thanks man, had the same issue when I ran rebirth. :)