Using a song in cl? Copyrights?? HELP PLEASE!!!?

From what I have read about the law, as long as you purchased the song (either by CD or on an internet site) and it is for a small audience (under 1,000 people) you are legally allowed to use it. I say again you must have purchased the song (no downloading from Limewire). Purchasing the song alows you to use it for small audiences.