Ooh! Another fan of the Arena music. We can all mostly agree that Daggerfall has some amazing compositions, but the music from the first game typically goes unloved.
What you want to check out is an old utility, http://www.tesnexus.com/downloads/file.php?id=8516. It was an effort to decipher Arena's file formats and rebuild the engine around it, and ultimately become a source port for the game akin to DaggerXL. Like all cool internet projects, it failed, but this early release is capable of extracting sprites, wall graphics, sounds, and the MIDI tracks from the game. Just to let you know, you have to use it with the floppy (free release) version of Arena, not the CD version if by any chance you have that. Have fun!