One common misconception is that you must register your copyrights with the United States Copyright Office in order for it to be considered copyrighted. The truth is that your stuff is automatically copyrighted the moment you create it in a tangible medium, like on paper or on audio recording. What the Copyright Office provides is not the copyright itself, but a certificate of registration of your copyright. This is a formal document issued directly from the Copyright Office to you that certifies that you are the owner of a work and that they have a record of your ownership on file at the Library of Congress.
Some people prefer to register their works with the US Copyright Office as a way to prove their rights in court if there was ever an infringement of their copyright. Songtrust does not register your works with the Copyright Office. However, you can do this on your own by completing the copyright forms available from the U.S. Copyright Office and including a copy of your work in a tangible medium.