June 1, 2007 -- Rolling Stone ranked it No. 1 on its list of the 500 greatest albums of all time.
And 40 years later, people are still talking about the Beatles' eighth album, "Sgt. Pepper's Lonely Hearts Club Band."
"It is ... when you sit down and listen to it from beginning to end ... a shockingly good record," said Joe Levy, the executive editor of Rolling Stone.
The song "Sgt. Pepper's Lonely Hearts Club Band" begins with, "It was 20 years ago today," and it was 40 years ago today that the Beatles showed the world a new way to play music.
Prominent critics and publication still say it's the most influential album of all time.
"It's sort of the album that announced the album itself as a work of art," said Eli Attie, a writer and musician.
"Sgt. Pepper" was recorded by the Beatles over a 129-day period beginning on Dec. 6, 1966. The album was released on June 1, 1967, in the United Kingdom and on June 2, 1967, in the United States.
"I don't know anybody who wasn't bowled over by it the first time they heard it," said Robert Christgau, a rock critic, who reviewed and applauded the album 40 years ago.
Ringo Starr, the Beatles' drummer, calls the album the band's "greatest endeavor."
"We had a huge liberated opportunity and could do anything we wanted," said Paul McCartney, the Beatles' frontman.
'Summer of Love' Soundtrack
Why the continued raves 40 years later? It was all about the timing, for one thing.
"It was a moment when there was an infatuation with the idea of hippies," said Christgau. "That was the so-called summer of love. And the Beatles record came out in June and provided a soundtrack to that romance."
It was also revolutionary for the Beatles themselves. It was about profound reinvention. It sent the mop-top boy band packing. They stepped outside of themselves and became Sgt. Pepper's band.
"It was gonna be boring to just make another Beatles album," said McCartney. "We'd stopped touring."
The Studio as Artistic Lab
And so they locked themselves up in the recording studio for four months -- unheard of at the time -- and remade not just themselves, but the concept of the rock album.
"It was sort of the beginning of the recording studio as an artistic laboratory," said Attie.
And the lyrics were brilliantly random poetry.
"We took the idea from the Daily Mirror, one of the tabloids," said McCartney. "There was some article -- there was always a mad article: In Blackburn there are 10,000 holes in the road and the city council has decided to fill them all."
Christgau remembers that even the details -- the lyrics on the sleeve and the kaleidoscope cover art -- were mesmerizing.
"A classic thing for a stoned person to do is sit and look at all of those faces and try to figure out who they are," said Christgau.
The Winning Formula
Why, ultimately, did Rolling Stone name "Sgt. Pepper's" the best rock 'n' roll album of all time?
It was the Beatles at the height of their creativity and collaboration.
"They were working together ... in that Lennon-McCartney formula for possibly the last time on 'Sgt. Pepper's,'" said Levy.
And the combination was staggering music.
"'A Day in the Life' is like a five-minute symphony," said Attie.
The influence on other artists was also immediate and profound. But in the end, the real reason we're still talking about the album is because nobody did it better, or even as well.
"The Beatles were just brilliant songwriters, and to some degree it's like those old Evil Knievel stunts -- you know, 'Kids don't try this at home,'" said Attie.
Happy Birthday "Sgt. Pepper." We'd still like to take you home with us.