Last night we saw (and heard) Phil Kline's Unsilent Night. It's an "outdoor participatory sound sculpture", which I first attended years ago. Mr. Kline provides a sound track (originally on cassettes) which people play on a large number of boom boxes as the group wends its way from Washington Square park over to Tompkins Square park. It's pretty cool since all the tracks are started at slightly different times and (at least with the cassette decks) run at slightly different speeds/pitches, so it's a moving, 3D composition, and it sounds really cool when you're walking inside of it.
In Tompkins Square, Mr. Kline comes around and asks each boom box to be shut off one by one, and then, it's over.
We had a great time, and we ended in the East Village just in time to make a holiday party there.