Over the course of my music career I've dealt with copyright issues quite a few times. A lot of my copyrights don't even show up in the online console because they were registered back when snail mail was the only way to do it.
Nowadays, it's much easier, faster and more reliable to do your copyright filings online. While the copyright.gov website is a little bit archaic and not as well programmed as it could be, it still serves the purpose admirably well of providing a portal for composers and artists of all kinds to create the copyright trail and documentation to make sure they are credited for their works.
One of the most asked questions I receive from clients and potential clients is, "now that I have a record (CD or digital release), what do I need to take care of, business-wise, to make sure my music is protected, and to be sure I'll get paid, if there is any pay to be gotten?" And of course, the first thing I do is educate them about how to copyright and protect their works. The second thing I explain is how to use BMI or ASCAP to collect mechanical royalties (but that is not covered in this section - I'll get to that in an upcoming video.)
U.S. Copyright Office - http://www.copyright.gov/