I figured out how to do it. I looked in the .json file in the .minecraft folder and I found there are 3 menu songs called menu1, menu2, and menu3. If you add a menu folder in the music folder in your resource pack you should be able to replace them with .ogg files.

Here is what it should look like:

http://i.imgur.com/VKJEhi3.png

http://i.imgur.com/6wXEfRI.png

EDIT: I just found out there is also a menu4 file so you need to add a 4th song as well.

Erm maybe this?
https://www.youtube.com/watch?v=nlcGp9Lh870