Another kind of copyright that will hold up in court is the old mail to yourself copyright. The reason?
You record your song and make a sheet of the melody and lyrics
You seal it in box, take it to a notary public and have it sealed
You mail it to yourself
When you recieve the box you take it to the bank and put it in a safety deposit box
Now you have a sealed container with your song on tape, the melody and lyrics in writing, all sealed in a box by a notary public, mailed with date stamped on the box and secured in a safe deposit box where the bank has a record of entry. In a court of law this will hold up. Probably better to get it done through a copyright office tho'.

Probably simpler. But, in dealing with a government agency, you never know who is handling your songs. Might be a relative or sibling to a song writer who wants to steal it. It's happened in the past.