“We hadn’t really rehearsed. As we were walking to the stage, he said, ‘Hang on, boys!’ And he went in the corner and vomited”: Assembled on 24 hours' notice, this John Lennon-led, motley crew supergroup marked the beginning of the end of the Beatles

John Lennon performs at the Toronto Rock and Roll Revival at Varsity Stadium in Toronto on September 13, 1969 (left), (from left) Eric Clapton (seated), bassist Klaus Voorman, John Lennon, and Yoko Ono.

“‘You’ll have to explain this a little to me. I have no idea what the Plastic Ono Band is. Is that Yoko’s band? Do we have to go naked onstage or what?’”

It's September 1969, and bassist Klaus Voormann is on the phone with his friend John Lennon, who'd spontaneously decided to do a set at the Toronto Rock and Roll Revival festival.