DOCUMENTARY PREMIERE: You’ve seen the movie. You’ve heard the soundtrack. You’ve even heard Joni Mitchell’s anthemic account of the seminal music and arts fair held in August 1969 in Bethel, NY. So why watch a new account, one that’s less about performance footage and more about the recorded music and national mood of the period? Because the perspective here is informative, and relatively clear-eyed. It also adds new elements to the story, such as the surprising fac