Our hotel was a few blocks away so we were there many times.
Because of the fest there was a small stage set up every night and sometimes in the afternoon with a variety of performances. I particularly liked the clown one afternoon who got a bunch of kids dancing and joked around a lot (of course, I don't know what he was saying); video below. He also got some adults up to do the same; they weren't as entertaining. There were dancing troupes in colorful costumes with very loud music - extreme bass that at times your whole body. One night there were probably several thousand people crowded together dancing. There were tents with little resaurants setup. This city knows how to let lots of people have a good time.
Maybe they should close off Harvard Square every Sunday - and branch off into Harvard Yard while they are at it...
Click here for pictures: