In the summer of 1967, when Sgt. Pepper’s Lonely Hearts Club Band was released, fans of The Beatles didn’t get together with friends and listen to the mono version of this landmark album.

I don’t recall anyone buying the mono version. Perhaps  if you couldn’t afford the $1 extra for stereo, because that’s all it was. But that’s not the point. The way to listen to Sgt. Pepper’s back then, as it is now, was in stereo.

I can remember at rehearsals and jams at the Aiardo Brothers house during the summer between the demise of the Bram Rigg Set and before I went off to school in Boston, we would take a break and listen to the entire album’s left channel.

Later the same afternoon we would listen to the whole album but just the right channel. Yeah, it was entertaining, listening to what George Martin and The Beatles were up to, but we were also trying to figure out what the hell they were doing as far as the recording process.

It wasn’t until several weeks later that I found out this album was recorded on a four-track machine. A four-track! Most studios in the States had long before installed eight-track recorders, including Syncron, later Trod Nossel, all the way out in Wallingford, CT, where my bands Bram Rigg Set and later Pulse worked out of.

Yet, The Beatles and Martin had produced an album on a four-track, albeit bouncing to a second four-track for many songs, and the album sounded extraordinary.

In a previous post on the recently released remastered versions of Help! and Rubber Soul, The Beatles albums that preceded these two, I wrote that bottom line the mono versions of those albums, even though I had grown up with the stereo, were my preference. OK, maybe not for Drive My Car and a few other tunes, but mono is the way to go for those: balanced, clear, direct and in-your-face punchy.

But this is where I get off the mono bus. First with Revolver and then more dramatically with Sgt. Pepper’s, Martin, who was learning what to do with stereo through Rubber Soul, was really finding his way more clearly and definitively.

The extreme right-left separation of the early albums is gone by Revolver, released in August 1966. Vocals are for the most part dead center. Sometimes as on Here, There And Everywhere, for effect, Paul’s lead vocal, in this case, is panned one way and those gorgeous background harmonies are panned mostly the other way.

Drums and bass are no longer swung hard to one side. They are panned usually left-center in the stereo image, giving them more presence in the mix. Where on each of the previous two albums only one song’s four tracks were bounced to another four-track to open up more tracks, all but three songs on Revolver were treated this way. Surprisingly one of the most complex sounding tracks, Tomorrow Never Knows, is one of the only ones that utilizes only four tracks.

Even when Martin uses a bit more separation, for instance on Eleanor Rigby, with Paul’s lead to the right and the strings dominating the rest of the spectrum, it works.

When you combine the songwriting, performance, vocals and clarity of the production on Revolver, there is only one way to listen to it and that’s in stereo. Now having said that the mono mix from The Beatles in Mono box set sounds awfully good. It  has a lot in common with all the other fine mono mixes that came before it. And this goes for Sgt. Pepper’s as well. But by the summer of 1967, it was a stereo world, and although I still like to listen to mono on occasion, it still is a stereo world.

It’s even more dramatic with Sgt. Pepper’s. The songs are really a cut below Revolver here, but the whole concept, package and idea of complete freedom this album gave the entire artistic community is only enhanced by the early yet accomplished stereo mix.

The vocals, in particular, on both these albums sound clearer and cleaner in the stereo mix. There is a nice spatial quality being established among all the voices and instruments that helps create the stereo sound field, two of the earliest examples of how powerful the stereo image is.

Also, there is an unpredictability in stereo. Subtle techniques such as having drums panned mostly left on the early verses of Good Day Sunshine, followed by a verse in which only the snare is present on the right, then hand claps and drums filter in on that side by the end of the song. These are lost or at least hard to distinguish in the mono mix.

The songwriting is first-rate on Revolver with McCartney’s Rigby, the beautiful For No One, Good Day Sunshine, hinting at more traditional music hall themes in his later work and the horn-laden Got To Get You Into My Life; Harrison’s exploration of the Indian tradition in Love You To contrasted with his funky, rocking blast at the British government in Taxman; and Lennon’s almost experimental tracks in Tomorrow Never Knows, with its hypnotic drum pattern and multiple tape loops and She Said, She Said, along with tracks we encountered here in the States before the release of Revolver on the U.S. release Yesterday And Today such as Dr. Robert, And Your Bird Can Sing and I’m Only Sleeping.

When you consider the artwork on both of these albums, you realize what a huge impact both made culturally beyond the music. The cover art of Revolver forever changed the way album covers were created. It was one of the most innovative and artistic to date, black-and-white portraits, embellished with a photo collage. Then the whole album package of Sgt. Pepper’s with the costumes, photo shoot, intense psychedelic colors, miscellaneous items and alter-identities of the musicians took everything up another notch.

The songs are eclectic on Sgt. Pepper’s and it really did imply to the music world, everything was fair game. The organ parts tape looped on Mr. Kite, Harrison’s most complete Indian composition in Within You, Without You, the raucous horns of Good Morning, Good Morning, the multiple track building on Getting Better, which required three bounce-downs, and the orchestra used chiefly as sound effect on the pinnacle composition A Day In The  Life.

But it was a fleeting moment. In less than a year the start of a back-to-roots movement had already started with Dylan and The Band and a move to country-rock and the singer/songwriters with The Byrds, Burritos and Mitchell, Taylor and King that even The Beatles couldn’t resist as they came around to a back-to-basics approach before they would break up.

From Rubber Soul to Abbey Road may be the most fruitful period for the greatest band of the ’60s. And the string of Soul, Revolver and Sgt. Pepper’s seems an unattainable, artistic summit but somehow they reached it.

Looking at the photos included in the booklets accompanying the stereo releases, the almost brooding portraits of the first six albums are replaced by the four of them looking so happy together and pleased with what they’re doing. You can hear it in the music.