HAT Music options/suggestions?

Can anyone suggest sources or sites for music that is eligible for use in the HAT contest (i.e., not copyrighted..)?

And while we're discussing the topic, do TV networks purchase rights to use songs in promotions? Before most big televised sporting events, there is a video montage set to some currently popular song/soundtrack that paints the story for the upcoming game/event. Do they pay to use the song? The song isn't the main attraction... the game is. s this how they get away with it?

What about sports arenas? They play all kinds of pop music and "Jock Jams" type stuff. Even a Mastercard commercial w/ "Who Let the Dogs Out?" featured the arena employee buying music... Do they pay a fee?

The HAT DVD will be showcasing our films, not the music. Does that make a difference if we site our sources? :wink

Anyone a lawyer?