Hi
I don't know about the US but here in the UK, a DJ should have a performance licence from PPL. It costs about £80 per year and allows you to publically perform any music so long as you don't alter the music i.e. Your own special mashup which lets face it, shouldn't be done anyway if you were anything of a good DJ lol!
Every good DJ should have a PPL which also covers you for podomatic and soundcloud because they are classed as public performance even though they could be looked at like file sharing.
Cheers
Nige
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