Legal Question in Intellectual Property in Illinois

What you suggest is known as a "poor man's copyright." Sure, you can make it so that you can prove you wrote a particular piece on a particular date. But, can you enforce it? No, not really. You may be able to make someone else quit using your song (injunction), but you can't sue for damages. Taking legal action is WAY more expensive than just registering your copyright.

You should follow Ms. Grosse's good advice and register your copyright. This is not, however, a "poor man's copyright" you speak about--the posting your songs. What you obviously do not know is that you already have a copyright. Copyrights are automatic upon creation of the work by the author, so your songs are already "copyrighted". The problem you do not recognize is that to legally enforce that copyright in a lawsuit in the USA you have to register it with the US Copyright Office (a branch of the LIbrary of Congress). (That is because US District Courts have exclusive original jurisdiction over copyright suits and current law requires you to have at least applied for a copyright registration to have standing to sue there. State courts do not have the right to hear copyright cases.) Fortunately, copyright registration is cheap and easy ($35 if you do it online) and all you need do is go to www.copyright.gov and follow the instructions. However, you may screw it up if you do it yourself the first time. So, the first time or two, I would strongly urge you have it done by a copyright lawyer, which will cost you another $100-300 depending on the lawyer.