Today Brian Epstein had invited The Beatles — along with Klaus Voormann, Lulu, Mick Jagger, Marianne Faithfull, and a whole bunch of other people — to a housewarming party at his new country estate in Sussex. This was a big deal for Brian, who’d been feeling increasingly insecure about his position in the Beatles camp.

And so John, George, Ringo and their wives loaded into John’s Rolls-Royce Phantom — newly repainted in psychedelic finery — and made the drive down. Biographer Bob Spitz sets the scene thusly:

“A Whiter Shade of Pale” provided the frothy soundtrack, blaring over and over from a turntable installed in the partition separating the passengers from the driver. An atmosphere of dreamlike abandon lingered inside the limo. John and George, who had been up all day and night – “perhaps all week,” according to George – in the wake of another LSD trip, wore their new identities unself-consciously. Draped from head to toe in flowing silks and satins, with braided scarves and strands of beads and amulets strung around their necks, they seemed disengaged from the obligations that pressed upon their public personalities…It was a gorgeous, sun-drenched day, warm and redolent of summer.”

Epstein had spared no expense on the party, stocking in lots of good food and wine and even lining the road leading to his house with balloons. But LSD was the star of the day. Guest Lionel Bart remembered:

The minute you walked through the door you got dosed. The boys were making the rounds, serving tea out of a china pot that had been generously spiked with acid. The whole party appeared to be tripping like mad; everyone was dancing around to the flame of a candle.

Everybody had a great time that day, it seems, except the two people whose time in the Beatles’ magic circle was just about up. One was Cynthia Lennon, whose relationship with John was already profoundly troubled and would only get worse from here. Cynthia, according to her memoir, took acid for the first time that day and had a profoundly bad trip, contemplating throwing herself out of an upstairs window. Another woman who was there claims that she never took anything and was faking. I don’t know that I personally care either way.

The other was Brian Epstein, who took it very personally when Paul called in the afternoon to say that he was picking up Jane Asher from the airport and wouldn’t be able to attend. As the day wore on, Brian drank heavily and brooded over the grand piano he had put in the living room so Paul could serve as accompanist for a sing-along, as was the tradition. Spitz again:

“This was to have been for Paul,” [Epstein] sighed in a quivering voice. “Especially for tonight, but he can’t come. The only one.”

It sucked the life right out of the party, until John and George stepped in to assure him of their love. Their affectionate hugs and the psychedelic fireworks that followed combined to rescue the evening from certain meltdown.

Sgt. Pepper played on in the background. It was the Summer of Love.