If you have the game, you can extract the music using a special program. I don't know the link for it, but I'm sure someone will tell you. It extracts it to several .ogg files without you having to move a muscle. You'll need an .ogg player such as winamp though. Media Player might play it aswell, but I'm not sure.
Apart from that, try the
Fan Pack which includes an audio cd with Divinity songs. Although I'm not sure wether they're DD or BD... Maybe they took the best songs from both games and put them onto one cd. But you gotta hurry up, cause there's only 500 fan packs... <img src="/ubbthreads/images/graemlins/ouch.gif" alt="" />