God Only Knows was written in half an hour, including two arguments between its co-creators. It's fair to say that assembling the cast of the BBC's new version of the song, all of whom reportedly gave their time for free, took a little longer, writes Alan Connor.
That half-hour, in autumn 1965, was a long time coming. Following a breakdown, Brian Wilson, chief songwriter for the Beach Boys, had paused to take stock for the first time.
First had been his childhood, in a musical band of brothers (and one cousin) superintended by his frustrated-musician father Murry, to whom the pushiest of parents can compare themselves favourably. Wilson Sr preferred the stick, or rather the belt, to the carrot. One of his punishments involved removing his glass eye and making the young Brian stare into the socket.
"When I was playing music," Wilson later recalled, "he couldn't hurt me."
Then, the success. Four unstinting years of effective isolation for Wilson, composing, recording and performing broadly similar faddish songs of surfboards and hot rods, with the odd moment of inspiration.
At a Hollywood party, he'd met a friend of a friend - Tony Asher, a handsome advertising executive who wrote jingles for Mattel toys and Gallo wines. A collaboration with the man who defined the Californian good life was an offer Asher couldn't refuse. He booked some vacation, daily visiting Wilson's Bellagio house to discuss the musician's preoccupations of music, "spiritual" literature and the nature of love. These conversations were fractured. Wilson, who had been denied a childhood, would break off to show Asher his mechanical parrots or to watch episodes of Flipper, an "aquatic Lassie" series about a dolphin, which invariably reduced him to tears.
In time, Wilson played Asher the pieces of music he had in mind for an album called Pet Sounds and Asher essayed some lyrics to fit the themes Wilson had in mind. When they got to God Only Knows, things didn't start well.
Wilson felt that "I may not always love you" was absolutely the wrong way to kick off a love song. Too negative, he insisted.
Asher, equally insistent, said: "Consider the next line." In Wilson's autobiography, he remembers this as: "But long as the stars are above you, you'll never need to doubt me." This is understatement of something enormous - I'll only love you until the end of time.
If you were feeling technical, you might call it "litotes" and Milton pulls a similar trick in his line: "Love, not the lowest end of human life". So does Raymond Chandler: "He was a big man but not more than six feet five inches tall and not wider than a beer truck." (Not everyone is so confident - at Wilson's second wedding in 1995, his daughters sang a version which began, "I know I'll always love you, as long as there are stars above you," though a second marriage ceremony is arguably no place for ambiguity.)
After the music had been dumb and goofy, and before it got too weird and spooky, there was Pet Sounds. So I guess that's why everyone loves it, because that's where everything was right” ~ Elvis Costello
Wilson was also worried about the G-word. In their second argument, Wilson wasn't sure he wanted to be the first to put "God" in the title of a pop song, but Asher convinced him that it was (a) spiritual and (b) ground-breaking, two of the qualities they were striving for.
(Wilson was right. In the US, God Only Knows found itself flipped with its B-side when the owners of radio stations and record stores announced they were unwilling to risk offending sensibilities).
So the lyric was added to Wilson's arrangement - a baroque affair which was to include accordions, French horn and, played by Asher, sleigh bells. While lush, it actually has fewer vocals than your average Beach Boys track.
Eight people's voices were recorded, including the subject of the song, Wilson's wife Marilyn, but the song we know has just three.
Brian gave the lead to his brother Carl with the advice: "Just take it real easy." At the end of the a cappella version on the Pet Sounds Sessions box set, Carl can be heard wondering: "How was that? Was that cool?"
This time, it's not understatement.
The other Beach Boys were not a little surprised by what they found when they returned from Japan. Wilson's cousin Mike Love in particular wondered about the value of artistic and commercial risks.
When the recording was finished, Wilson told the band that he had found the music by praying to God. Love, ever the antagonist-pragmatist, muttered, "Pray to God it sells." The record company, too, questioned whether Pet Sounds was really a Beach Boys album.
They called time on the sessions, leaving one track without its vocals, and then considered shelving the whole project. At the last fraught meeting with the Capitol executives, Wilson answered their questions using a tape recorder on which he had recorded himself saying "yes", "no", "no comment" and "can you repeat the question?"
Sometimes the nay-sayers are right, and a musician's "personal project" is disastrous folly. Few would charge Pet Sounds with that.
God Only Knows gets a special kind of praise, such as becoming the favourite song of a Beatle - Paul McCartney, the one to whom Wilson perpetually and disparagingly compared himself.
Wilson, indomitably fretful, responded to McCartney's praise by locking himself in the changing hut next to his swimming pool, on the basis that if God Only Knows were worthy of such praise, it must all be downhill from there.
"I'm a has-been," he concluded as McCartney stood outside, "and a wash-up."