Woodstock was big but "Woodstock" was bigger. The many millions in London and Leeds and Lyon and everywhere else in the world who bought tickets to see the subsequent film got a better, drier, more visible and audible entertainment experience than had been available to most of the people who were in Bethel when the festival took place.
Alvin Lee died today. Lee led the Nottingham blues band Ten Years After who (unlike The Band and Creedence Clearwater Revival) were bright enough to sign the contract with the makers of the film. "Woodstock" made them. No act has been more identified with one performance of one song on one day than Ten Years After were with their 11-minute performance of "Going Home". It was as fast as rock and roll can get while still being rhythmic. In the film it was shot close up with Lee's Roman profile occupying the greater part of the mile-wide screen while the other members of Ten Years After were consigned to the splits. It was a young man's fantasy come to life. I bet the boys who were to go on to form the Ramones were watching.
I went to see the film repeatedly. One Saturday afternoon at the Odeon Leicester Square the whole cinema applauded at the end of "Going Home". Actually applauded a band who weren't there. I do believe some people may even have stood.