Lord, was just going to post a quick comment but got carried away. Apologies. Excellent post and good comment about the ‘Englishness’ of the music. Jimi may be a prophet without honour in a lot of the States, but to me he sits on the right hand of God (with SRV on the left, lol).
I bought my copy of Sgt. Pepper’s in 67 and have played it over and over again. But I think the emphasis placed on it now is a bit overblown. Yes, it was a seminal work, but so were Pet Sounds, Are You Experienced, Piper at the Gates, etc. The Beatles had been experimenting with unusual instruments and arrangements since Rubber Soul, in many ways Sgt. Pepper’s can be seen as the next step in a logical progression. A lot of critics call it the first concept album, but then again a lot of critics say Zappa's 'Freak Out' was the first.
Pepper’s was certainly a concept album, at least in the creation of a fictitious band, the packaging and careful song arrangement, though Lennon always vehemently denied that he wrote the songs as part of a coherent concept. Zappa thought the album was awful, that the Beatles had sold out. The Mother’s 68 album’ We're Only In It For The Money’ was a direct parody. Maybe Zappa had a point, given that the awful 'Magical Mystery Tour' followed on it's heels.
A lot of people say Pepper's greatest legacy was in it's innovative recording techniques. Though some highly original techniques were used on the album, particularly in double tracking the vocals, the basic techniques for multi-track recording and dubdown were already well established. Pet Sounds, Are You Experienced, Axis Bold as Love and Piper at the Gates of Dawn made extensive use of them. Phil Spector had been doing the Wall of Sound thing for years. Perhaps Peppers popularized the techniques, but it certainly didn't invent them.
Jimi released the single Hey Joe/Stone Free in 66. In early 67 he released Are You Experienced and later in the year Axis Bold as Love. Electric Ladyland in 68. Pet Sounds came out in 66 also, as well as The Bluesbreakers with Eric Clapton, which a lot of people think put Brit Blues on the map. Floyd released Piper in 67. So popular music was already moving in a lot of different directions prior to Peppers.
The Airplane released Surrealistic pillow in 67, another psychedelic direction by an already established band. The Stones released 3 albums, Flowers, Their Satanic Majesty’s Request and Between the Buttons.
Their Satanic Majesty's Request is often viewed as a cheap knock-off of Sgt. Peppers, the Stone's attempt to cash in on psychedelia, but in fact recoding began in Feb of 67 and ended in October of the same year. It was well in the works by the time Sgt. Peppers was released. So I don't think it was inspired or particularly influenced by Peppers, rather it represented a different psychedelic direction taken by a different band. I actually think it holds up very well.
There were also initial releases by The Grateful Dead, The Doors, David Bowie, and Pink Floyd. I don’t see much Pepper’s in any of those releases.
In 68 Jimi released Electric Ladyland, a work of at least near genius. Van Morrison released Astral Weeks, Simon and Garfunkel released Bookends. Johnny Cash did Folsom Prison Blues. Floyd did Saucer Full of Secrets, the Byrd's Sweetheart of the Rodeo kick started the alt country movement, The Doors released Waiting for the Sun. Wheels of Fire from Cream, We're Only In it for the Money by Zappa and the Mothers. Again, not a lot of Pepper's except for We're Only In It For the Money, which wouldn't have been recorded except that Zappa was so pissed off with Lennon and McCartney.
That said, it's a great album, and is still on my regular playlist. But let’s not over-hype it’s influence.