As I understand it, the Sounds folder is for alternative sounds, the originals being hidden inside the code to prevent accidental sound losses. Several years ago when this system was new someone told he had Sing, sing, sing by Glenn Miller Orchestra as the title tune. Being a copycat I did the same. The tune is so good I sometimes enjoy listening to it entirely before logging into the game!
@Hap, isn't it funny that some people want even the title music off, some want to listen certain music through their entire gaming session. The latter can further be spliced into those who like adrenaline pumping music to boost their performance while others want WW2 era tunes for immersion.