It's up to you as to when to register your copyright. You have to assess the risk. No, the old idea of sending the songs to yourself through registered mail is not effective. I would imagine that having a copy of sheet music notarized might work (but only in a limited way...as Vikki said, no court costs or penalties). Also, I'd guess that sending several copies to different people, maybe to a lawyer and/or some other, presumably, upstanding individuals, might provide a songwriter with witnesses. However, nothing provides the protection here in the U.S. that the Library of Congress does. It costs a bit, but they're in the protection racket.

You've got to know your limitations. I don't know what your limitations are. I found out what mine were when I was twelve. I found out that there weren't too many limitations, if I did it my way. -Johnny Cash

It's only music.
-niteshift

Mike Dunbar Music