This is a documentary from 1975 with interviews with Martin Scorsese, Werner Herzog, and Steven Spielberg. If you click to watch Part 4 (under ‘Clip Selection’ you can go straight to it, just keep clicking the clips to see the next one), Dustin appears in the video at about 8:49 and talks about his role in Lenny Bruce, the message Lenny was trying to send, and about art and expression in general. His first wife, Anne, is also in the beginning of the clip.