It was a long time ago and I've never practiced in this area, but I did take copyright law (& entertainment law) in Law School from the Beatles' lawyer. IIRC, the following considerations apply. First, you do not need to copyright your song to prevent others from stealing it. So long as you can prove you wrote it first, you can still sue someone for unauthorized use and collect damages. One way to prove you wrote it first is the poor man's copyright where you mail yourself a copy and leave the envelope sealed. The reasons to copyright are twofold. First, it clearly establishes that you are the author as of the date of copyright, and secondly, by registering your copyright, you are entitled to statutory damages in event of unauthorized use. This means that if someone rips you off and you prevail in court, they owe you at least an amount of money as provided for in the copyright laws. This applies even if the song stealer never made any money off of your song - they still have to pay you some money. If you don't register a copyright and your song is stolen and you prevail in court, you are only entitled to actual damages - the actual profit the thief made off of your song. That's my recollection, but please consult with a copyright/patent attorney before taking any action in reliance on the above.
Bill, tgo
(Message edited by lbpesq on June 29, 2008)