San Francisco is no stranger to free music. Long before Napster ushered in the age of pirated music, Bay Area bands were willingly performing free concerts in the city's streets and parks. Many of those events had political undertones to them and perhaps even a slight undercurrent of anti-capitalist thought. The largest annual free music festival in the city, Hardly Strictly Bluegrass brings world-class performers that are, indeed, hardly strictly bluegrass. Oddly enough, the audience has a big-time capitalist to thank, as the event is a gift to the city by billionaire investment banker Warren Hellman.

That's all fine and dandy and this year's event, held this past weekend in the same area of Golden Gate Park that also hosts Outside Lands and Power to the Peaceful, brought record-breaking crowds. It was projected that well over half a million people attended over the three days, effectively shutting down traffic routes, causing a public transportation nightmare and making iPhones seem temporarily useless. The festival also brought many musical surprises, such as Elvis Perkins sitting in with Dr. Dog (which, actually, wasn't that big of a surprise).


But the big moment came on Saturday morning when Robert Plant -- who was not on this year's schedule but performed last year with Alison Krauss -- sat in with Buddy Miller for a cover of Hank Snow's "I'm Moving On."

"This is like going to school for me," said Plant. For the rest of us, it felt a little more like recess.