Humpback whales sing some of the most beautiful songs in the animal world. It’s not just “woo, woo, woo”—their songs last 10 to 15 minutes and have a definite form, usually consisting of five or six unique phrases. Only the males sing, which has led many scientists to theorize that they croon to attract females. The hole in this argument, though, is that no one has ever seen a female whale show any interest in a male’s song.