Bob Dylan’s instant reaction to the recently completed album Paul McCartney brought by his London hotel room for a quick listen in the spring of 1967 may not sound like the most thoughtful analysis ever offered, but it still hit the nail on the head. “Oh I get it,” Dylan said to Paul on hearing Sgt. Pepper’s Lonely Hearts Club Band for the first time, “you don’t want to be cute anymore.” In time, the Beatles’ eighth studio album would come to be regarded by many as the greatest in the history of rock and roll, and oceans of ink would be spilt in praising and analyzing its revolutionary qualities. But what Bob Dylan picked up on immediately was its meaning to the Beatles themselves, who turned a critical corner in their career with the release of Sgt. Pepper’s Lonely Hearts Club Band on June 1, 1967.

Writing in The Times of London in 1967, the critic Kenneth Tynan called the release of Sgt. Pepper “a decisive moment in the history of Western civilization,” but 30 years later, Paul McCartney called it a decisive moment of a more personal nature. “We were not boys, we were men,” is how he summed up the Beatles’ mindset as they gave up live performance and set about defining themselves purely as a studio band. “All that boy [stuff], all that screaming, we didn’t want any more,” McCartney said. “There was now more to it.” With Sgt. Pepper’s Lonely Hearts Club Band, the Beatles announced their intention to be seen “as artists rather than just performers.”

Sgt. Pepper is often cited as the first “concept album,” and as the inspiration for other great pop stars of the 60s, from the Stones and the Beach Boys to Stevie Wonder and Marvin Gaye, to reach for new heights of creativity. For the Beatles themselves, 1967 marked not just a new creative peak, but also the beginning of a three-year period in which the group recorded and released an astonishing five original studio albums, including two—1968’s The Beatles (a.k.a. “The White Album”) and 1969’s Abbey Road—that occupy the 10th and 14th spots, respectively, on Rolling Stone magazine’s list of the Greatest Albums of All Time. Also in the top 15 on that list are Rubber Soul (1965) at #5, Revolver (1966) at #3 and Sgt. Pepper’s Lonely Hearts Club Band at #1.