On June 1, The Beatles’ magnum opus Sgt. Pepper’s Lonely Hearts Club Band, arguably the greatest album released in the popular music age, turns 50, and will receive a deluxe repackage, and countless column inches with breathless writers singing the praises of the endlessly inventive record.

The critical praise in print has not always been so kind, as McCartney points out in a recent chat with MOJO, for the magazine’s upcoming issue.

“We were always being told, ‘You’re gonna lose all your fans with this one.’” McCartney told MOJO. “And we’d say, ‘Well, we’ll lose some but we’ll gain some.’ We’ve gotta advance.”

Given the whiplash pace the band operated at, they weren’t strangers to befuddled reviewers from the old guard questioning whether these young moptops had lost their bloomin’ marbles.

Sgt. Pepper did actually get a terrible review in the New York Times,” McCartney explains. “The critic said he hated it, thought it was a terrible mess, and then he was on the streets all week and heard the talk, heard what people were saying, and he took it back [in a subsequent Village Voice piece], recanted after a week: ‘Er… maybe it’s not so bad.’ But we were used to that. ‘She Loves You’ was ‘banal’. But if we liked it and thought it was cool, we would go for it.

“…I mean, George doing ‘Within You Without You’, a completely Indian record – it was nothing anyone had heard before, at least in this context. It was a risk, and we were aware of that.”

The review McCartney singles out was particularly mean-spirited, reading in part: “The sound is a pastiche of dissonance and lushness. The mood is mellow, even nostalgic. But, like the cover, the over-all effect is busy, hip and cluttered. Like an over-attended child “Sergeant Pepper” is spoiled. It reeks of horns and harps, harmonica quartets, assorted animal noises and a 41-piece orchestra; On at least one cut, the Beatles are not heard at all instrumentally.”

It’s not too surprising the squares didn’t dig it – after all, the times were changing, and — as McCartney once quipped — The Beatles didn’t even do the same thing once.