Hey John,

As far as I'm aware, anyone can record or perform anything once they song is public.

For TV licencing, they are licencing the recordingfor which you get paid, and hence the market for sound alikes.

You don't however, receive broadcast royalties, which go to the writer and publisher of a copywrited work.

This does not apply to advertising, where the contract is made with the writer, and hence excludes you from using other folks' material in that case.

At least that's my understanding, and please correct me ( anyone ) if I have the wrong take on it.

cheers, niteshift