I think that the issue of copywrite may be different than the issue of licensing rights with regard to such a modified song. Remember, that there is no obligation to register a song for it to have copywrite protection. The registration is primarily to serve as evidence of the copywrite.

Tom


Thomas Shea

Thomas Shea - Songwriting
http://www.soundclick.com/thomasshea

Justice - Songs
http://www.soundclick.com/justice-nebraska