Others have compared the song's deceptively advanced harmonic structure to the work of classical composers such as Delibes, Bach, and Stravinsky.

Wilson produced the record between March and April 1966, enlisting about 20 session musicians who variously played drums, sleigh bells, plastic orange juice cups, clarinets, flutes, strings, French horn, accordion, guitars, upright bass, harpsichord, and a tack piano with its strings taped.

"God Only Knows" is among the several songs that Brian Wilson and Tony Asher wrote for the Beach Boys' Pet Sounds album.

Asher felt that it was the pair's most effortless collaboration, remembering that Wilson "spent more time tweaking the instrumental part than we did writing the words!

Biographer Mark Dillon suggested that Wilson's inspiration would likely have been the vocal layering on "You Didn't Have to Be So Nice", a recent hit by Sebastian's band the Lovin' Spoonful.

[8][nb 1] In later interviews, Wilson said that he wrote "God Only Knows" as an attempt to match the standard of the Beatles' album Rubber Soul (released in December 1965).

Writing in his book about the album, Jim Fusilli noted a closing phrase Wilson had once written to his wife in 1964: "Yours 'til God wants us apart.

At the time the song was written, referencing "God" in a title or lyric was generally considered a taboo for pop music, and there had been at least one recent instance of a record being banned from radio for having words such as "hell" or "damn".

"[18] Dillon wrote that referring to God may have also been viewed as "a square move" due to the nascent decline of traditional religion in the United States.

"[25] Cash Box described the song as a "slow-shufflin' tender, romantic ode about a guy who is so much in love that he doesn't think that he could go on without his gal.

"[31] According to musicologist James Garratt, the "tonal plasticity" made the song innovative not just in pop music, but also for the Baroque style it is emulating.

[37] He likened the use of sustained strings to those employed by Wilson on the Pet Sounds tracks "Don't Talk (Put Your Head on My Shoulder)" and "I'm Waiting for the Day".

[39] "God Only Knows" starts with an A major chord accompanied by the sounds of accordions, harpsichord, and French horn, which are soon joined by bass, tambourine, and sleigh bells.

According to Lambert, "The ear wants to hear the music in the key of A, and is just starting to feel that it's okay to dismiss the horn note [until the proceeding verse section].

"[28][nb 4] Garratt writes, "While the idea of presenting the verse harmonies in the subdominant in the bridge was not new, what is striking here is the smoothness with which the song drops back into the original key – a moment rendered even more arresting by the truncated three-measure phrase that precedes it.

"[44] The song ends with a final coda[23] that features repeating vocal rounds[31]—a centuries-old technique that was highly unusual for pop music of the era—[45] with triplet fills played on a drum kit.

"[49] Bruce Johnston, who joined the band a year earlier, later said that he "didn't realize just how great" Pet Sounds was going to be until he witnessed this session.

To address this issue, pianist Don Randi suggested to Wilson that they play the parts in staccato, rather than in full quarter notes.

[52][nb 6] The ending was a fuller arrangement that included the voices of Marilyn, her sister Diane, and Byrds producer Terry Melcher.

[57] Dillon suggested that Brian may have changed his mind on the lead partly to address concerns over the large percentage of singing roles he was granting himself for the album.

'"[59] The 1996 stereo mix of the song, created by Mark Linett for The Pet Sounds Sessions box set, does not feature the same singers on the fade-out.

[67] Record World reviewed the song as a single, and called it a "very pretty rockaballad with low key chanting by ... the Beach Boys" and "a meaningful love lyric teens will find irresistable.

[61] The film featured the group (minus Johnston) at Lake Arrowhead, flailing around in grotesque horror masks and playing Old Maid.

[76] Reviewing their late 1966 European tour, Melody Maker critic Mike Henessey decreed that the live arrangement "sounded a little thin compared with the recorded [version].

"God Only Knows" is often praised as one of the greatest songs ever written,[34] as the Beach Boys' finest record,[82] as Carl's best vocal performance,[83] and as Brian's most quintessential work.

[84] Granata deemed "God Only Knows" a musically and technically impressive accomplishment that Wilson and the Beach Boys never repeated on their subsequent records.

He wrote that the song "has resonated with generations of music fans simply because of its concept", before concluding, "The entire world will listen to it for years to come.

[89] The 2013 video game BioShock Infinite contains a turn-of-the-century barbershop quartet that sings the song while floating past the player on an airship.

[82] "God Only Knows" has been covered by a wide variety of artists that includes Andy Williams, Neil Diamond, Olivia Newton-John, Glen Campbell, David Bowie, Toni Tennille, Joss Stone, Mandy Moore, Michael Stipe, Rivers Cuomo, JR JR, Avenged Sevenfold and Taylor Swift.

[47] The Beach Boys Guest Session musicians (also known as "the Wrecking Crew") The Sid Sharp Strings Technical staff ‡ Sales+streaming figures based on certification alone.