Well, you don't want anybody to steal your ideas, i.e. your music or your lyrics, do you? How can you make sure that your copyright is observed? It is actually quite easy. What you need is a method to prove that you were the first who had that particular idea. But you can prove this neiter by keeping it a secret, nor by asking people more or less friendly that they may observe your copyright conditions. You prove it by actually publishing your stuff and making it available to as many people as possible. So, if the question ever arises which version of a text or melody was there first, you will have witnesses on your side.
The internet makes it quite easy to achieve this. Just find a server which will publish your stuff and put a time stamp on it. It has to be a server you cannot manipulate yourself. And it should be a server which you trust to be still there when you need it to prove your rights (so, rather make it two or three servers, you never know). My current favorite is the Internet Archive. It's Internet "Wayback Machine" has been around for a considerable time, so I trust it to be of endurance. The web address is: http://www.archive.org/. There is no charge to become a member and start storing your MP3 files or lyrics.
I put my stuff there, of course:
http://www.archive.org/search.php?query=creator%3A%22Bernd%20Harmsen%22 (if you want to download my lyrics collection choose the 2nd edition)
Part of my stuff has been stored on the "Wayback machine" since 2002:
http://web.archive.org/web/20021213194028/ourworld.compuserve.com/homepages/har/song-chords.htm 
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