With a disclaimer and explaination of how licensing works. Time and again someone has to explain to newbies about the licensing procedure..
What brought this to mind is the resent mention of Beatles tunes..
Here is an example of what maybe involved in procuring a licence..
http://wiki.answers.com/Q/Who_owns_the_Beatles%27_music
I'm would guess most cases are not this deep, but many would involve artist, composer, producers and not to mention legal situations like the Beatles..
Just my thoughts..
Happy guitar day..
Gordon