If you want to get just about any song ever, do a Google search like this one:
Just replace the artist and song name with your choice. If you want an album instead of a song, just replace the song name with the name of the album instead. Look for files with larger sizes if you want higher quality songs or albums.
No comment on the ethics behind this – you feel how you want about not paying anyone for the music you enjoy. If you feel bad about it, you can always get your music from a creative content license site like Jamendo where the music is free and you can pay the artist if you want to do so.