Download something called " LimeWire" You can download anything including music, movies, games, applications, software, etc... You can put all of the music you download onto iTunes.
I bite the bullet and use Imesh Premium service for 9 bucks per month. From there, I use "Protected Music Converter" to remove the usage rights to allow me to play the mp3's/wma's on my phone, etc.
I just search it the internet like for example I found this page http://www.emp3world.com/mp3/119689/Chris Brown/Crawl Then follow the instruction Note: Left click or (Right click, "Save Target As") Its so easy.. No need to download any software or buying in itunes
i use limewire, bearshare, torrentz, seeksy, etc.. sometimes i go to mp3000.net.. but becareful with virus..
Mostly I prefer torrents. Often I'm not interested in downloading individual songs but rather albums or discographies. Even if you want one song or one picture etc out of a torrent that's no problem because you can deselect all the files except the specific one you want (depends on how the files are organized in the torrent whether you can do this or not). It is so easy to get a virus from the p2p programs such as Kazaa/Vuze/Limewire/Ares and so forth. Torrents are often much safer. And for the love of all that's holy, use PeerBlock while you're running a p2p program. Otherwise you might end up getting a disconnect notice or worse from your ISP.