Before The Beatles, you had pop music and you had art; after The Beatles, the idea that you could get both in a single three-minute shot became commonplace. If “I Want to Hold Your Hand” made the competition look quaint, “Strawberry Fields Forever” made it look obsolete: stone bowls in an era of cupped hands. They were around for 10 years, and the culture has been reeling ever since. Formed in Liverpool, England, in 1960, the band—John Lennon, Paul McCartney, George Harrison, and Ringo Starr (the replacement for Pete Best)—didn’t have big plans at first. In 1962, they were still ducking beer bottles at late-night shows in Hamburg; six months later, “Beatlemania“ was a safety concern. Listen to that opening chord on “A Hard Day’s Night” or the proto-psychedelic vibe of “Ticket to Ride” and you can already hear them pushing against the confines of pop’s sound and form. By the mid-’60s, they’d become ambassadors for the counterculture, tackling drugs (“Lucy in the Sky With Diamonds”), Eastern spirituality (“Tomorrow Never Knows”), and the limits of consciousness (“Because”). They also became one of the first bands to use the studio as an instrument, creating works whose density and complexity (“I Am the Walrus,” “Ob-La-Di, Ob-La-Da”) couldn’t be replicated onstage.