I maintain a website called the adlib music archive. It is a place you can visit in order to download videogame soundtracks that use the Ad Lib sound card. Many Sierra games used Ad Lib / Sound Blaster as a primary music option, and now you can FREELY download many great Sierra (and other game) musics and enjoy them again. I custom rip, edit and time all music files for the best possible quality. They’re stored in original Ad Lib format, so they sound just the same as they did when played through the game.
You will need a music player to listen to the music. I recommend AdPlay for DOS, since it gets the best sound quality (uses real Ad Lib OPL2 chip for playback). However there’s also AdPlug for WinAMP and Linux. You can find all of these @ http://adplug.sourceforge.net/