[Silverthornne]

Oh, it's really easy to do. Morrowind uses music in MP3 format. What you do is you locate your MP3's and look for the Music Folder in Morrowind. The structure goes (if default installation):

Program Files\Bethesda Softworks\Morrowind\Data Files\Music

In the music folder you will find one for exploration, another for battle and a "special" folder. They're named for what they do, for music to play while exploring or fighting, drag it to the appropiate folder. The game will just shuffle the tracks. You don't need to rename anything (unless you have the unlikely event of 2 identically named tracks). The special folder has music for the title screen, dying, and leveling up. In order to replace those tracks, you do need to rename them so I'd suggest backing up the originals before you do it if for some reason you decide to change these tracks.