|The "poor man's copyright"? From Flikr.
Copyright law is somewhat murky, and some of you may have wondered: if I write (or arrange) my own music how do I copyright it? Before I try to demystify this, I should start with a disclaimer: I'm not a lawyer.
Okay, with the disclaimer taken care of, let me tell a story: when I was in high school, I was (unnecessarily) worried about people stealing my creative work. I heard somewhere that to protect yourself, you should seal your music in an envelope, mail a copy of the music to yourself, and never open the letter. And I did this a few times. Well, it turns out that this method of copyright protection is folkloric, and really unnecessary. It wouldn’t make a difference in music copyright litigation (though patents might be different).
So what do you need to do, under current copyright law? Well, not much. You don't even need to put a copyright symbol and year on your work, and you don't need to register. Unless of course, you want to sue people, in which case you do need to register. And you aren't going to sue people unless they are making substantial money from your creative work.
If you do decide to register, it's not too difficult (I hear, as I haven't done it myself). You can register a single author for $35 online on the US Copyright Office website. The copyright office doesn't do much verification; if there's a problem, it will be sorted out with litigation. In other words, act now and ask questions later. For more, see "Taking the Mystery Out of Copyright" from the Library of Congress. Why is the Library of Congress doing education about copyright? Well, it's more than just than that a librarian's job seems to entail explaining copyright to the public—the Copyright Office is actually a part of the Library of Congress.
One final thought: some things you just can't copyright—you can’t copyright ideas, for example. But you can copyright the way that idea is expressed. What about the murky space in between? Well, again, that's what litigation is for.
Have any of you tried to register something with the US Copyright Office?