Lennon, notoriously inept and ignorant at technical specifics and intricacies, had no idea what he was actually asking George Martin to do. If he had understood, he might not have made such a request. Nevertheless, it is a testament to George Martin's and Geoff Emerick's technical skill that they found a way to make it work.
The problem is that take 7 is in B-flat major at a tempo of 90 beats per minute, while Take 26 is in C major and at a tempo of 108 beats per minute - both higher-pitched and faster. To splice these two takes together as they were (i.e. without altering the original in any way) would have sound like this:
So how to make these two disparate takes fit together to the point of not sounding edited?
Using tape methods of recording, pitch and tempo are inextricably intertwined - if you change one, in doing so you necessarily also change the other. (In the digital age, of course, computers can alter pitch and/or tempo independently of each other, but in the 1960's that was not the case.) In what is probably the greatest coincidence in the entire Beatles saga, the two takes were proportionately equivalent - meaning that if take 7 were sped up, and take 26 slowed down, they could match both in tempo and tonality.
But this, too, presented problems: "George and I decided to allow the second half to play all the way through at the slower speed; doing so gave John's voice a smokey, think quality that seemed to complement the psychedelic lyric and swirling instrumentation. Things were a bit trickier with the beginning section; it started out at such a perfect, laconic tempo that we didn't want to speed it up all the way through. Luckily, the EMI tape machines were fitted with very fine varispeed controls. With a bit of practice, I was able to gradually increase the speed of the first take and get it to a certain precise point, right up to the moment where we knew we were going to do the edit. The change is so subtle as to be virtually unnoticeable" (Emerick, page 140). (Parenthetically, I can hear the tempo difference, but what remains a mystery to me is why there is not a corresponding difference in pitch. The whole point of this "splice story" is predicated on the fact that if you change one, you necessarily also alter the other - and yet here it appears that somehow the tempo was changed while the pitch was not. I have absolutely no idea how...)
After many hours of work, George and Geoff had a finished product. Though expertly masked, the splice can still be heard at precisely 1:00. (It is easiest to hear the edit if you listen to the drums.)
There is another major edit at the end of the song that also survived to the released recording. "There is the end section of the orchestrated version of the song, where the rhythm is too loose to use. In spite of all our editing, I just could not get a unified take with complete synchronicity throughout. The obvious answer would have been to fade out the take before the beat goes haywire. But that would have meant discarding one of my favourite bits, which included some great trumpet and guitar playing, as well as the magical random mellotronic note-waterfall John had come up with. It was a section brimming with energy, and I was determined to keep it. We did the only thing possible - we faded the song right out just before the point where the rhythm goes to pieces, so the listener would think it was all over, then gradually faded it back up again, bringing back our glorious finale" (Martin, page 22-23).
With Lennon (finally) satisfied, "Strawberry Fields Forever" was (and remained) complete. It was now ready for release.
Emerick, Geoff with Howard Massey. Here, There and Everywhere: My Life Recording the Music of The Beatles. Gotham Books, New York, NY, 2006.
Martin, George with William Pearson. With a Little Help from My Friends: The Making of Sgt. Pepper. Little Brown and Company, Boston, MA, 1994.