On March 30, 1967, The Beatles strolled into Michael Cooper’s photographic studio at 4 Chelsea Manor Studios, London, prepared to turn the music world’s expectations on their head. Or maybe they were just bored. After all, if you’re already the most famous band on the planet, why not have a little fun with it? The idea was Paul McCartney’s, who by this point was firmly asserting himself as the band’s creative shot-caller. His original sketches were a fever dream of them standing like dignitaries before a grand floral clock, surrounded by friends, admirers, and whoever else seemed interesting enough to be immortalized in cardboard.

McCartney handed his doodles off to Robert Fraser, the art dealer and all-around tastemaker who seemed determined to keep The Beatles hovering somewhere between high art and full-blown self-parody. Fraser enlisted pop-art darlings Peter Blake and Jann Haworth to turn McCartney’s eccentric vision into a coherent design. The artists’ solution? A surrealistic collage depicting The Beatles as the fictional “Sgt. Pepper’s Lonely Hearts Club Band,” standing triumphantly before a motley crowd of wax figures, hand-painted cutouts, and the kind of cultural references that would make an art historian’s head spin.

Whether McCartney was completely original in his concept is a murky matter. A Swedish brass band called Mercblecket had released an album in 1964 featuring artwork suspiciously similar to what Sgt. Pepper’s would become. The theory goes that McCartney saw the record when the group entertained The Beatles during their Stockholm visit. Of course, McCartney’s never admitted to the alleged inspiration, but if there’s anything the Sgt. Pepper’s cover celebrates, it’s the absurdity of fame and influence.

The roster of figures crowding the cover included everyone from Bob Dylan to Marilyn Monroe to Aleister Crowley. John Lennon, naturally, pushed for more controversial picks—Jesus, Gandhi, even Adolf Hitler. EMI drew the line at those suggestions, citing a desire to actually sell the album in India and, well, anywhere else. But Lennon’s impulse for shock value was still embedded in the DNA of the final product. Meanwhile, Blake and Haworth worked feverishly to paint the life-sized cutouts and assemble the chaotic spectacle.

Ideas came and went. Paul’s friend John Dunbar tried to sell them on the brilliance of a completely abstract cover with no text, the kind of thing meant to convey how little they cared about commercial success. Another concept involved dressing the band in Edwardian garb and posing them in a cluttered sitting room, but that idea was also tossed aside in favor of the surrealist, patchwork fantasia Blake and Haworth were assembling.

Details were layered in like confetti at a particularly pretentious parade. Jann Haworth contributed the floral arrangement at the base of the image—“Beatles” spelled out in red hyacinths, complete with a yellow flower guitar that looks like it’s on the verge of dissolving into psychedelic goo. The drumhead emblazoned with the album’s title was painted by fairground artist Joe Ephgrave, who had no idea he was about to create one of the most famous pieces of pop art in history. Shirley Temple’s doll, wearing a sweater reading “Welcome The Rolling Stones,” winked from the corner. Elvis Presley was conspicuously absent, not because anyone forgot him, but because McCartney decided he was “too important and too far above the rest even to mention.”

When the band arrived for the shoot, half of them were high, because of course they were. Lennon even boasted, “If you look closely at the album cover, you’ll see two people who are flying, and two who aren’t.” Ringo, as usual, summed it up with a shrug: “Have a look at the cover and come to your own conclusion! There’s a lot of red-eyed photos around!” The session took three hours and cost around £3,000—a small fortune compared to the £75 spent on Revolver’s cover, but considering the audacity of the concept, practically a bargain.

And then there was the aftermath. The sheer influence of the cover was immediate and unavoidable. Frank Zappa went for a far less reverent approach. His 1968 album We’re Only in It for the Money lampooned the entire Sgt. Pepper’s affair, depicting the Mothers of Invention in a grotesque caricature of the original cover. That Zappa even bothered to ask McCartney’s permission only to be politely told to take it up with the lawyers makes the whole thing even more hilarious. It was a parody born out of admiration, mockery, and a healthy sense of frustration with the music industry’s newfound obsession with self-importance.

Ultimately, the Sgt. Pepper’s cover was an elaborate inside joke performed on the entire world. It was The Beatles embracing their own mythology and mocking it at the same time. Maybe that’s why it still feels relevant. It was a moment when pop culture, art, and outright ridiculousness collided and somehow created something brilliant.