One of the minor questions in this "History of Collective Joy" is that of where dancing comes from, why it should be a universal action and pleasure. She hypothesizes that humans, or proto-humans, learned to do it to frighten off predators. The idea is that a group of people moving in unison look like a threat as big as the group, not a bunch of threats only as big as the puny individuals.
Now we know it works for giant honeybees, which do the wave to repulse wasps.
I can't remember if Ehrenreich extends the hypothesis to the possibility that moving in unison actually makes a group more dangerous to attack, but cooperation and communication are how humans now survive, and of course we do both with music. Dancing at predators might not be a false signal of a false size, but a true signal of a true skill, just as the bees also dance to each other when the wasps are gone.
The dance of the bees is a language; well, it has a grammar in the programming sense, although it's probably Not Done to refer to it as a language in the natural language sense... sketches how the capacity for language might have arisen from the pre-processing needed to hit a rabbit with a thrown stone; the capacity needed to dance well is going to be harder to calculate (he neatly shows that the accuracy and speed needed to hit a rabbit, compared to the slowness with which signals travel through arm-muscles, mean that the whole throwing action is laid out in the brain before it's sent to the muscles to be executed there). Some of dancing is exactly unlike throwing the rock: there are many ways to bring a foot down at a given time, but the problem is to coordinate among all the dancers what that time is. And this implies a need for communication, and mirror-neurons and maybe rhythm, fired up exactly when the muscular activity is high. Irresistable just-so stories.
Find in a Library: Dancing in the Streets
Find in a Library: The Throwing Madonna
So wrote clew in History.