Mostly because music is something that I feel everyone can relate to on one level or another. Whether it's the feeling they get when they hear the beat, rhythm, or whether it's the power and meaning behind the lyrics, there's that special something about everyone's favorite song that pulls them in. Music is something that is native to almost every know culture on the planet. To not have a music forum, would be to exclude a variety of interesting threads and posts from the board.
So to get things started, I'm going to make a bunch of poll and opinion threads. Everyone likes those threads. Good ice-breakers, I think.