4Shared is a very good and reliable file-sharing website, although it isn't exclusively used for music mp3's. But it is at least more reliable than Limewire.
Legally free download websites would normally require you to pay a certain fee. However, be aware since there are many websites which will charge you even though they offer illegal software. I would...
Anything that is expected to be paid for is illegal to download for free. Usually, music, movies, games, and most software is copyrighted, which means that whoever has the copyright owns it....