Music's got some key features of an evolved adaptation: It's universal across cultures, it's ancient in prehistory, and kids learn it early and spontaneously.
The point is not that all humans do it, but that only humans do it, at least in the way humans do it. We speak of bird songs, but birds don't exactly compose individual songs. They make sounds that we think of as songs and by which we can identify the species, since every bird in that species that sings a song(s) sings the same song(s).
Am I the only person who thinks these attempts to explain everything in terms of evolution actually only repeat, using evolutionary terminology, what we already know? "In order to protect his genitalia, man developed jockstraps."