It was 56 years ago Sunday (February 13th, 1967) that the Beatles released their double A-sided single of "Strawberry Fields Forever" and "Penny Lane." The single contained two of the first three songs recorded for the group's upcoming Sgt. Pepper's Lonely Hearts Club Band album. (The other song, "When I'm 64," was saved for the album.) The songs broke the group's then unprecedented six-month stretch since their last single, "Yellow Submarine" backed by "Eleanor Rigby."

The new songs, which touched upon the group's Liverpool upbringing, were a study in contrasts, with Paul McCartney's more literal "Penny Lane" borrowing heavily from the sound of the Beach Boys' then-recent Pet Sounds album, and John Lennon's introspective "Strawberry Fields Forever" breaking new ground in both record production and song structure.

In a classic example of less being more, late-Beatles producer George Martin told us that the limited technology of the 1960's in no way held back the Beatles from recording timeless classics: ["And I think in fact, if I had more than four tracks recording Sgt. Pepper, I don't think it would've been any better than it turned out. The music itself was so good, that no matter what you did with it — provided you did it reasonably, technically well — it would've survived."] SOUNDCUE (:14 OC: . . . it would've survived)

We asked Elvis Costello about what many consider among the Beatles and George Martin's finest hours, the 1967 double-A-side single release of "Strawberry Fields Forever" and "Penny Lane": ["Obviously, as I got older and understood what was going on musically on the record a little bit, and got to work with Geoff Emerick and got some understanding of, like, what they went through to create those records technically, y'know, what was involved in the engineering and the recording process and the layering of it. You realize what a great work of imagination it was — unprecedented, really, in popular music at that point. And, like a lot of great things, it probably invited a lot of bad imitation, but it's an indelible record. I would say, the best single. . . The best Double A-sided single in pop music."] SOUNDCUE (:32 OC: . . . in pop music)

At a dinner party at manager Brian Epstein's house with the Beatles and their significant others, Pete Townshend and Eric Clapton were the first two outside musicians to be played the new tracks. Upon Townshend's recollection, when asked what they two thought about what they just heard, the Who leader was left speechless — Clapton, on the other hand responded, "Could we please hear it again?"

Paul McCartney says that above all the other emotions he has regarding having John Lennon as his best friend for a substantial part of his life, he's still in awe of their musical connection: ["I've got so many great memories, and I feel very privileged. Y'know, I'm the guy he wrote with — that's pretty cool. And we wrote some great stuff and enjoyed it — never really sweated it. We normally finished a song in about three hours, and can't ever remember coming away from a session without having a song."] SOUNDCUE (:17 OC: . . . having a song)

Author Christopher Sanford, who wrote the biography titled McCartney, says that even during the Beatles days, it was McCartney who was constantly pushing the group to find new sounds in the studio: ["Paul was the guy, I think, who was saying, 'Y'know, we can take this to a new direction. We can try these instruments that have never been tried. Let's get George Martin to have an orchestra playing out of tune!' And that was all McCartney."] SOUNDCUE (:13 OC: . . . was all McCartney)

The single was a global hit, with "Penny Lane" eventually topping the U.S. charts on March 18th, and "Strawberry Fields Forever" going on to peak at Number Eight.

In Britain, the single was kept from the top spot by Engelbert Humperdinck's "Release Me," marking the first time since their 1962 debut single "Love Me Do" that the Beatles failed to top the charts in their homeland.

The single, which was the Beatles' first after retiring from touring, featured the first of many Beatles songs the group never got to perform live.

In 1990, during McCartney's first performance in Liverpool since Lennon's death, he performed "Strawberry Fields Forever" in a medley with the Beatles' "Help!" and the Plastic Ono Band's "Give Peace A Chance" as a moving tribute to his fallen former partner.

Paul McCartney introduced "Penny Lane" into his live shows on his 1993 world tour.

Christopher Sanford On Paul McCartney Breaking Musical Boundaries :

Paul McCartney On Songwriting With John Lennon :

Elvis Costello On ‘Strawberry Fields Forever’ And ‘Penny Lane’ :

George Martin On Technology Not Holding The Beatles Back :