Originally Posted by fielder's choice
How is the easiest way to do that? And is it legal to upload a song that isn't mine?
The easiest way to upload a song is to find a friend who has his own website and ask him if he'll host it for you. Second option: Google "free webhosts". They exist.
As for the legalities, it depends on the song. In most cases, no one will ever know you are using the song except for the handful of people who visit your Myspace page, but if it is a major label artist it is illegal. It is illegal too for any artist, but most independent artists and labels don't sue people for listening to their music. Summary: No one will know or should care that you are using it on your Myspace page, so you should be fine.