Changing Startup Theme/Music?

[Loader]

So when I first bought Sims 3, I bought it with University Life. So whenever I start the game, I will get the loading screen with the University Life theme and music. Since then, I have obtained a few more DLC, and was wondering if there was a way I could change the startup theme to any of the other DLCs? I own University Life, Seasons, Generations, and Supernatural.

[Haeloth]

The game's main menu only contains three themes, one comes with the base game, one with Late Night, and another one with Pets. So you are actually listening to the base game theme at the startup everytime because you don't own Late Night or Pets. If you own any one of them in the future, the music will be chosen randomly from the available options. Just wanted to make that clear first. I don't know how to change them though.

About the "visual theme" of the startup screen, well you can use this mod: http://modthesims.info/d/465870

Edit: Oh by the way I didn't mention how the visual theme is chosen by the game. It always choses the latest released expansion or stuff pack you have, in your case that is University Life. If you buy Into the Future, it will always show Into the Future loading screen and there is no way to change that since that is the last released DLC for this game. (Unless you use the mod mentioned above)