You have to pay for a copyright. And they do expire and become public domain if not renewed. There is also a way to get permission or a lic. to use copyrighted material as long as you pay royalties or %. Can't remember what that's called off hand, but some musicians will do that (cut a deal) to re-record others work. If you have Michael Jacksons money you just buy the co. that owns the rights.
http://ipwatchdog.com/2009/07/01/michael-jackson-and-the-beatles-copyrights/id=4363/