Martin Scorsese served as film editor for the Woodstock documentary film, and was indeed there in person. I couldn't find any pics of him AT the festival, though, so hopefully I depicted him fairly accurately.
[1969; MG runs into someone not-yet-famous] (Martin Scorsese, into a walkie-talkie) "Okay, I wanna get some good shots of some people dancing in the audience, be on the lookout for that..." (MG) "Whoa... Are you Martin Scorsese?" (MS) "Um, yes.." (MG) "WOW, FUCKIN' A, man! The FAMOUS FILMMAKER himself!!!" (MS) "Who, ME???" (MG, not getting the hint that this is Scorsese's first major film project) "HELL YEAH! Oh shit, this is SO COOL! Dude, I really LOVED Goodfellas, King of Comedy..." (CW) "MOONBAT! What the FUCK are you DOING?!?!" (MG) "...and fuckin' TAXI DrMMFRR!" (CW, covering up MG's big mouth) "Uhh, please excuse my friend here. I think he had too much of that 'Brown Acid' that they were talking about." (MS) "Okayyyy..."