A little site I happened to wander across while doing my daily browsing of classic games is Cosmic-Dreams

If there’s some good ol’ music from classic DOS, Amiga or some other games you just can’t seem to find mp3/ogg’s of, this just might be what you’re looking for! And if you don’t find what you’re looking for, you can make a request!
Cosmic-Dreams posts music from MS-DOS games in mp3/ogg format. And in
the case of MIDI formats from the original game scores, they too are
rendered beautifully in mp3/ogg format. (if you have a dreadful MIDI
output like I do, these are well worth the download than just relying
on the original MIDI’s)

The posted tracks are in the forums. There’s even a section for
requesting tracks from certain games for those who don’t find what
they’re looking for. I recommend those who check the site out to
especially look into downloading the Darklands and The Immortal
soundtracks, very good stuff!

The site still seems to be in its infant phase, but hopefully it’ll grow, since there’s A LOT of classic DOS games I wouldn’t mind nabbing the audio from. So head on over, check out the songs, make some requests, and of course say “hi!” to Skatoony!