is there a mod that allows the playing of more tracks.
I'd check out "Better Music System", http://tesnexus.com/downloads/file.php?id=26892. There also is a RELZ thread here somewhere (IIRC) but I cannot find the link right now, may edit my post later on.
It provides more music choices based on location. I use it, it is very good. I have a lot of music in my "Explore" folder for example, and sooner or later BMS has played them all, but the choice for the next piece is always random which I like. I think you also need to download an OBSE plugin "Enhanced Music and Control" or something for BMS to work fully. I'm quite sure you will like BMS.
Edit: http://www.gamesas.com/index.php?/topic/1062801-relz-bettermusicsystem-20/ but it is locked and there seems not to be a new one. Member searching for "side777" lets you find his other content, probably worth a look
[haegintmusic]