This mod replaces the music played at the main menu with this acoustic piece. The music itself was given with permission from Misha Colbourne, cleaned up in Audacity, and applied to the mod.

https://www.youtube.com/watch?v=_swhSwiTbZo

Some have said that the volume is low, it is indeed quite low in comparison to the original title theme. However I believe it works to provide the right ambiance. Sound in the main menu is natively balanced by the game, if you cannot hear the music, it is likely your volume in windows is not 100%. There is no reason to have it any lower than 100%. Here is an article which touches on line level out, and the fact that windows 100% is a 0db gain setting. http://www.tomshardware.com/forum/41421-63-speaker-volume-windows-software-volume#.