LONDON — It was 20 50 years ago today on June 1.

On its release in 1967, the Beatles’ eighth studio album, Sgt. Pepper’s Lonely Hearts Club Band, wasn’t universally loved. “The mood is mellow, even nostalgic. But, like the cover, the overall effect is busy, hip and cluttered. Like an over-attended child, Sgt. Pepper is spoiled,” the music critic Richard Goldstein wrote in The New York Times. Never mind that the album became an almost instant hit. “Oh, I get it,” Bob Dylan told Paul McCartney, when Paul played a bit of the band’s new music for him in 1966. “You don’t want to be cute anymore.”

A half-century later, Sgt. Pepper’s, which ushered in the rock ‘n’ roll “concept album” — a collection of songs written around a central theme — and inspired musicians from Pink Floyd to Radiohead to Stevie Wonder, will be celebrated anew this month and next.

Liverpool, where the Beatles grew up, will host a “Sgt. Pepper at 50” event through June 16 featuring musicians, choreographers, visual artists and poets taking part in a range of cross-disciplinary projects that honor each of the record’s 13 songs. Capitol Records is releasing reissue packages in an array of formats.

“It’s crazy to think that 50 years later, we are looking back on this project with such fondness and a little bit of amazement at how four guys, a great producer and his engineers could make such a lasting piece of art,” McCartney wrote in the introduction to the super-deluxe box-set anniversary edition of Sgt. Pepper’s that includes a new stereo remix, 33 previously unreleased tracks from the recording sessions at Abbey Road Studios in London and a rare making-of-the-album documentary.

The super-deluxe box-set edition is available on Amazon for $117.99. The regular anniversary CD version costs $13.99.

McCartney and Ringo Starr are the two surviving members of the Beatles….