You bought the disc. You are allowed in most countries to make a new copy for personal use. You may sell the original CD, but not sell the copies that you made.
You see, the kicker is that you do not take off a song from a CD, the song is still there. You make a copy. It is an extension of a right that goes back to hand-copying texts from a book, or photocopying it for personal use, and so on.
