A crowd of the famous dead assembles behind four men in electric silk. That is the first thing the eye registers on the front of Sgt. Pepper's Lonely Hearts Club Band: a tiered gathering of heroes and ghosts, waxworks and cardboard, pressing in around The Beatles as they stand in DayGlo military uniforms of blue, magenta, orange and gold.

In front of them, red hyacinths spell out BEATLES across a bed of flowers, arranged with the solemnity of a grave. The image reads less like a band photograph than a ceremony, and less like a snapshot than a puzzle. High culture and pop culture stand shoulder to shoulder in one impossibly democratic assembly, everyone equally lit, equally present, all of them staring back.

Nobody glances at this cover. It insists on being read, and it has been read for more than half a century: as remix, as manifesto, as coded message, as funeral. The heroes were hand-picked, one by one, and every prop scattered at the band's feet was placed for a reason. What those choices were, who built them, and why the picture still refuses to settle is the story below.