The book How Music Really Works has some decent ideas about the evolution of music.

On the contrary. That is exactly the sort of rubbish that gives evolutionary psychology such a bad name.

The idea that something like music -- an extremely high-level byproduct of human cognition -- could be explained directly as an evolutionary adaptation is absurd enough. (Imagine trying to give a Darwinian account of why chess pieces move in the way they do.) The invocation of sexual selection -- the process that explains the peacock's fancy tail -- borders on the ludicrous. Sexual selection is only a candidate explanation in cases of marked sexual dimorphism -- a significant phenotypic difference between males and females, as in the peacock. The fact (if true) that professional musicians statistically tend to be males doesn't come anywhere close to cutting it.