I have a question. Isn't it that music is copyrighted and is not allowed to be played on public performances? Why is it on some shows, an auditioning crew/ dancer is allowed to use their own music, while it may be possible that it is not copyrighted for a public performances (unlike set music given by the shows, which is probably given permission)
Hmm.. There's fair use (called fair dealing in the legal codes of other countries) that allows limited use of a certain copyrighted material. I'm not sure how that applies to music performance, so I'll run down some other things I found.
There are performance rights organizations that collect royalties from groups that intend on using copyrighted works in a public setting. I'd presume that you would need to pay royalties to get your hands on permission to use music in a non-free setting.
I was also looking around about how shows such as American Idol freely make use of music, and I found an answer somewhat.
Oh, I just read these things a few minutes ago. Hopefully someone with better credentials comes in. I wonder why you'd want to ask this question of a site mainly composed of young male flash gamers.