I saw him play Sept 13, 1969 at the Toronto "Rock & Roll Revival", at the University of Toronto's Varsity Stadium.
That was a wild show with Gene Vincent (backed by the Alice Cooper band), Bo Diddley, Little Richard, Chuck Berry, John Lennon ("Plastic Ono Band" with John, Yoko, Eric Clapton, Alan White and Klaus Voorman), with The Doors headlining and closing the show. (probably other performers as well)
Security was ... porous, and I crawled under the stage to backstage. I spoke to Little Richard and Bo Diddley briefly before they cleared unauthorized people out of the backstage area.
RIP.