Photo: Michael Ochs Archives/ Getty Images.

Sixty-one years after releasing their first single, "Love Me Do," the Beatles have released their latest. "Now and Then" reflects, in the three words of its title, its antecedent, which is on the other side. The single accompanies a new version of the group's greatest hits albums Red and Blue.

It could be considered a cynical marketing ploy, but the history of its long gestation suggests otherwise. Within the story from "Love Me Do" to "Now and Then" is the love story of John Lennon and Paul McCartney, which is also ours.

More than half a century after the breakup of the Beatles, their songs continue to permeate our lives. We sing them in kindergartens and stadiums; We mourn them at weddings and funerals, and in the privacy of our rooms.

The Beatles' songs continue to speak to us so directly because they are vehicles for conveying feelings too powerful for normal speech. Lennon and McCartney were intense young men who grew up in a time when men weren't encouraged to talk about their feelings, either in therapy or with each other. His emotional education came from music, especially the music of black artists such as Smokey Robinson, Arthur Alexander, and The Shirelles. Almost everything they felt—and they felt a lot—they poured into the music, including their feelings for each other.

"Now and Then" was not conceived as a Beatles song. Well after the group's dissolution, Lennon wrote it on piano during his period of retirement from the public scene in the late 1970s. He recorded it on a tape recorder and saved it. In 1994, his wife, Yoko Ono, discovered a pair of cassettes of her husband's demos of songs and contributed them to the Beatles retrospective Anthology project.

On the label of one of them, Lennon had scrawled "Now + Then," as if to highlight that particular song. But because the sound quality was so bad (George Harrison called it "rubbish"), "Now and Then" didn't get very far.

But McCartney never forgot her. He sent the demo to Peter Jackson, the director of the Beatles documentary Get Back, who used cutting-edge audio technology to clean the tape so thoroughly that it sounded as if Lennon was back in the room.

"There it was, John's voice, crystal clear," McCartney said. "It's very emotional." McCartney and Ringo Starr, now in his 80s — and George Harrison, posthumously — added parts.

Why did McCartney pursue this project for so long? He's busy enough, and in the last five years alone, he's worked on solo albums, a memoir, a musical, and a world tour.

"Now and Then" is a sweetly melancholy song, but perhaps not on the level of the Beatles when they were together. Giles Martin, producer of this new track and son of legendary Beatles producer George Martin, has a theory: "I have a feeling that 'Now and Then' is a love letter to Paul written by John," he says, and believes that "that's why Paul was so determined to finish it."

Although it has been described as a friendship, rivalry, or partnership of convenience, the best way to conceive of the relationship between these two geniuses is as a love affair. As far as we know, it wasn't a sexual relationship, but it was passionate: intense, tender, and tempestuous.

Lennon and McCartney met as teenagers in 1957. They were talented, charismatic, and damaged. McCartney had recently lost his beloved mother to cancer; Lennon had gone from mother to father to aunt without ever feeling loved. His mother, Julia, whom he adored, was killed by a reckless driver a year later.

Grief brought these motherless children together, and so did laughter. But music was the strongest bond of all. They decided to write songs together, a promise they kept until the breakup of the Beatles, and dreamed of creating a whole private world.

Within a few years, the world became his dream. The microculture that germinated among them became the philosophy of the Beatles, which left a lasting mark on all of us. We may not be as optimistic as they were back then, but we are imbued with their relentless curiosity, wild imagination, and belief in the possibilities of love.

Throughout their relationship, Lennon and McCartney used songs to say things to each other that they might not feel able to say to each other's faces. Lennon said he wrote the 1968 song "Glass Onion" (one line reads, "the walrus was Paul") as a way to let McCartney know they were still friends.

After the breakup of the band, they maintained a dialogue at a distance, in songs full of recriminations, regret and affection. Lennon, hurt by the insults McCartney had included on his Ram album ("You took your lucky break and broke it in two"), recorded "How Do You Sleep?", a spiteful and hurtful attack on his former songwriting partner ("the only thing you did was yesterday").

McCartney responded with "Dear Friend," a melancholy call for a cessation of hostilities ("Is this really the borderline?").

After this, a truce was given. For the rest of the decade, until Lennon's death in 1980, they made hesitant efforts to re-establish their friendship from across the Atlantic. McCartney and his wife, Linda, visited Lennon in the United States, but it is possible that they reserved their true confidences for the songs.

In "Let Me Roll It", McCartney does a virtual impersonation of Lennon. On "I Know (I Know)," Lennon sings, "I love you more today than I did yesterday," over a guitar solo based on his last direct songwriting collaboration, "I've Got a Feeling."

"Talking is the slowest way to communicate," John Lennon said in 1968. "The music is so much better." In a sense, the music of the Beatles, which brings so much joy and comfort, is the glorious fruit of male repression. We like to think that we live in a more emotionally enlightened age. We've learned to talk things through. However, sometimes I think that's a kind of evasion, or a failure of the guts. We have woken up from sleep, and yet we seem to be more confused than ever.

Carl Perkins, rockabilly guitarist and singer and Beatles hero, collaborated with McCartney after Lennon's death. One day, he played for McCartney a song he had written for him with the line, "My old friend, won't you think of me once in a while?"

McCartney wept and left the room, leaving Linda to reassure a shocked Perkins. "She said [those were] the last words John Lennon said to Paul in the hallway of the Dakota Building," Perkins told Goldmine magazine toward the end of his life. Lennon "patted him on the shoulder and said, 'Think of me once in a while, old friend.'"

We can understand why a song called "Now and Then" might be so important to McCartney, and we can guess what he hears in Lennon's lyrics:

If we must start over

Then we'll be sure

That I'll love you...

Every once in a while, I miss you

From time to time

I want you to be there for me.

In those last two lines, we can hear McCartney's aging voice joining that of his old friend.

Last year, I was in the audience at MetLife Stadium in New Jersey at a McCartney concert. The first encore of the concert was a virtual duet with Lennon from "I've Got a Feeling," featuring footage from the 1969 rooftop concert.

It might have been a cheap gimmick, but when McCartney turned to the giant image of his young friend, I cried, along with thousands of others.

Technology can revive the state of reverie, even if only for a song.

(From The New York Times)