Check out this video of the Beatles, still acting like a real band as they lay down "Two of Us," which would later show up on Let It Be. There are many cool things about this clip, including the fact that you get to see how thick John Lennon's glasses were -- the dude must have been totally blind -- and that Paul McCartney evidently invented the air tie. Plus, I never knew that was Lennon whistling at the end. I always thought it was Paul. Maybe he had already died by that point.
Finally, when I went to see the Beastie Boys at Red Rocks in 2004, I was astonished to see MCA with gum in his mouth. But here, you can see Lennon blissfully chomping away. Maybe that's where Yauch got the idea.