I never really like one of the songs in the towns that play when your inside, its called mus_town_day_03, I don't know the real name.
Anyway I found the song a little depressing, so I replaced it with the song mus_explore_day_4 aka Silt Sunrise, which was my favorite song from Morrowind.

::::::Installation::::::

1. Extract to your Skyrim\Data directory.

2. Check "Load loose files" in your launcher under data files.

3. No more depresing music.

4. Profit.

If you don't know which songs I'm talking about listen to these.

I replaced this.
mus_town_day_03: http://www.youtube.com/watch?v=-I4fG-joJzs

With this.
Silt Sunrise: http://www.youtube.com/watch?v=ktytY5uIjag

If you hear any strange noise in the youtube videos don't worry because its not there in game.