Here's three of my favorites
Joe Cocker "With a little Help From My Friends"
Arlo Guthrie, Coming into Los Angeles
If you ever get a chance to buy or rent the "Alice's Restaurant" DVD do it (it should be cheap by now) The movie is really dated, but they have a track where Arlo, (now 61) explains the filming of the movie scene by scene, what was going on at the time, basically telling stories, some about the movie, some not.
Crosby Stills & Nash, Suite Judy Blue Eyes
I was listening to Kim Mitchell (of Max Webster) on the way home from work tonight, he's the afternoon guy on Q. Anyway he was talking about the WoodStock sound quality of the performances on the Woodstock DVD. The guitars weren't staying in tune, the performers had to keep resetting the sound levels in mid performance etc.
Kim's theory was that the sound engineers, roadies, set up crews, who were working all day, were just too high, to keep it together. Makes sense
Anyway I had to work that weekend.