Oh for Christs sake when will you people get the hang of 'copyright', we've had this issue before on mudcat, steveiemon is right, you don't have to register, pay a fee or anything else! if you have arranged a song in a particular way with a particular accompaniment then the copyright to THAT particular recording is already yours automatically!!! If you're that unsure go and get yourself a copy of the copyrights designs and patents act of 1988 from H.M.S.O. (I've got one)you don't have to stick words to songs, tapes or anything else in registered letters and post the to yourselves, YOU'VE ALREADY GOT IT!!!
...I'm sorry...I do get worked up about these things...