Most have interpreted the question to mean scripted movies set in the world of R&R — it doesn't say that but it's cool.
I'll go with Monterey Pop all the way. Amazing acts, at their best, a great mix, and captured the geist at its absolute peak.
And what actors could ever play Janis, Otis, Jimi?
Woodstock was more about the event than the Music — about mud, chaos, bad acid, where to piss — still great though. Took my Dad to Woodstock when it came out. We came in on Joe Cocker. Dad blew a gasket: "I'm not going to watch this cretin!!" I convinced him to stay. Two hours later, when Joe came on again, I said "OK Dad, we can go now" and he said "No no! I want to see this guy again. He's great!"