Today, says The Beatles Bible,

John Lennon woke up regretting having agreed to perform at the Toronto Rock and Roll Revival festival that evening. Eric Clapton, however, was eager to play, and convinced Lennon that it was too late to back out.

And so Lennon, Clapton, Klaus Voormann, and Alan White climbed onto an airplane, where they attempted to rehearse on the way to Canada. (They had never played together before; until then, Plastic Ono Band had been just a name John used for his solo records.) It did not go well. According to Mark Spitz’s The Beatles,

Over the Atlantic, [John] and Clapton huddled in the galley behind the last row of seats, attempting to go over key signatures and arrangements. Clapton remembered: “We picked out chords on the guitar, which you couldn’t hear because we had nowhere to plug in, and, of course, Alan didn’t have his drums on the plane with him.” It also didn’t help matters that both John and Clapton were strung out, fighting off waves of nausea from withdrawal symptoms.

Meanwhile, back in Toronto, not only did festival promoter John Brower have to shoehorn the Plastic Ono Band into an already crowded lineup — including Chuck Berry, Bo Diddley, Chicago Transit Authority, Alice Cooper, Jerry Lee Lewis, Little Richard, Gene Vincent, Junior Walker & the All-Stars, and headliner the Doors — he had a hard time convincing people that Lennon was actually coming.

Word on the street was that he was lying and just trying to scam people into buying tickets. Local radio refused to cover the story. The Vagabonds Motorcycle Club, which Brower had hired to escort Lennon from the airport to the gig, was threatening terrible things if they rode out there to find no Beatle. [The Global News]

It’s a good thing he didn’t know at the time how close he came to suffering the wrath of the Vagabonds; though keep in mind this is a Canadian biker gang we’re talking about, so by “terrible things” they may have meant a sharply worded rebuke.

In any case, about 10 P.M. local time, a black limousine accompanied by Brower and 80 Vagabond motorcycles arrived at the Varsity Stadium of Toronto University. John, Yoko, and co. were escorted by police to their dressing room, where they spent two nervous hours waiting to go on. According to Clapton, “John just stood in the dressing room, which was admittedly rather tatty, beforehand saying,  ‘What am I doing here? I could have gone to Brighton!’” He spent most of the time, though, vomiting from some combination of stage fright and junk-sickness.

Finally the time came for the Smart Beatle and his pick-up band to take the stage. It was at this point that emcee Kim Fowley — a rock legend in his own right, whose story I have no time to get into today — may have invented an important piece of concert ritual. Says Mal Evans:

He had all the lights in the stadium turned right down and then asked everyone to strike a match. It was a really unbelievable sight when thousands of little flickering lights suddenly shone all over the huge arena.

Then it was showtime.

They were underrehearsed and strung out. John couldn’t remember the words to any of the songs, even the ones he had written. “I nearly threw up [during] ‘Cold Turkey,’” he said. It mattered not. He was John Fucking Lennon, and his charisma carried the day. (Clapton, for all his talent, could never hope to channel one-tenth the wattage.)

The buzz was incredible. I never felt so good in my life. Everybody was with us and leaping up and down doing the peace sign, because they knew most of the numbers anyway, and we did a number called Cold Turkey we’d never done before and they dug it like mad.

After leading the band through three rock classics (“Blue Suede Shoes,” “Money,” and “Dizzy Miss Lizzy,”) and three originals (“Yer Blues,” “Cold Turkey,” and “Give Peace a Chance”), John turned the mic over to Yoko, who shrieked through 15 minutes of utter chaos. Afterwards, the audience might well have been wondering what they had just seen. What they had seen was the end of John’s life as a Beatle and the beginning of his new career.

The night was still not over — the Doors closed the show, finishing their set with (of course) “The End.” It all makes sense somehow.