Miller - "Darwin argued that music evolved mainly by sexual selection through mate choice—and that we're uncomfortable acknowledging that fact. He wrote back in 1871 that, "The impassioned orator, bard, or musician, when with his varied tones and cadences he excites the strongest emotions in his hearers, little suspects that he uses the same means by which his half-human ancestors long ago aroused each other's ardent passions, during their courtship and rivalry." He knew that music didn't need to have a "survival value" for the individual or the group; it could spread through purely reproductive benefits. He suggested that the more musically talented proto-humans attracted more sexual partners, or higher-quality sexual partners, than their less-musical rivals. We see sexual selection for music in many other species—insect song, frog song, bird song, whale song, and gibbon song—so I think that's a reasonable default theory for how humans evolved music. It's the theory to beat."
- two scientists discussing the origins of music - an interesting read.)
and i have to say that having had the opportunity to watch humans in clubs i'm inclined to agree with miller and darwin..