As stated by the band, the track is "an attempt at an unconventional song structure" as it does not have a chorus and it is divided into three parts. In a track by track analysis, Jonny Buckland revealed: "We've been trying for about two years now to record a song that didn't have any choruses, didn't really have any verses, was just sort of, you know, one section, another section into a different section, and "42" was the first time we were able to do it successfully." Chris Martin added: "Although every time we tried that, we've called the song "42", that's about the ninth "42"." About its influences, Chris said: "It's our attempt at [Queen's] "Bohemian Rhapsody", [Radiohead's] "Paranoid Android", all those songs that we love, that go A-B-C-D-E-F-G in structure."
Guy Berryman also mentioned The Beatles as an influence for the song: "There are definite sort of Beatles influences on th[e] song, if people were to pick up on that, but I think it sort of became our own thing, and we've tried songs with A-B-C sections before and they haven't worked so I think we were all really quite surprised and pleased when it actually came together as a tangible new piece."
In an interview for tabloid newspaper The Sun, Chris jokingly said the song is "our attempt at a Radiohead song. No, it's our 97th attempt at a Radiohead song, but the first one that's worked." In an Entertainment Weekly article, Chris told the song is "a nod to U2's "40" and the Smashing Pumpkins' "1979". I don't think you can try to be the best band in the world without having a song that's a number."
Writing and composition
"42" was described as "a multi-sectioned piece about death" divided into three parts and doesn't have a chorus itself. The first part is a ballad with piano and strings, which then transforms into an uptempo rock arrangement with a guitar solo. The song ends with a multi-instrumental part.
About its structure and writing process, Will Champion noted: "There's obviously three totally distinct sections, but whenever we tried to play them through, they sounded like, "How on Earth is that going to work? How are you going to join those two sections?" And it's a real lesson in if you're bold about things like transitions between sections that don't sound like they're gonna work, if you really just hit them hard and don't try and be to clever about it. The confidence who kind of pulls it off rather than, you know, that doesn't sound silly, it just sounds natural, but you really have to let it do its work."
Etymology and meaning
In the comic science fiction series created by Douglas Adams, The Hitchhiker's Guide to the Galaxy, the number 42 is considered to be the Answer to the Ultimate Question of Life, the Universe, and Everything. When asked by Q magazine if the song title has anything to do with the series, Chris said: "It is and it isn't. 42 is my favourite number. 42 is just perfect. We've got two John Lennon songs, this and "Violet Hill"."
About the meaning of the lyrics, Chris explained to MTV: "Well, the whole record is — if it were a Notorious B.I.G. record — it'd be called Life and Death, it's just that... Maybe because we've had some people close to us who we've lost, but some miracles — we've got kids. So, life has been very extreme recently, and so both death and life pop up quite often. It's called "42" because it's my favorite number. And I think it's probably in Will's top three favorite numbers too."
Mikael Wood from Spin praised the track's experimentalism, reviewing: "Even when they're not looking beyond the borders of home, they do satisfyingly weird things to their music, as in "42", which starts out in plaintive piano-ballad mode, then transforms without notice into a juddering psych-punk jam."
In a ranking of the band's entire discography, in celebration of the 20th anniversary of the release of Parachutes, NME praised the band's boldness, saying: "Martin pines about the ghosts that dog him on one of the artsiest tracks on the uber-artsy ‘Viva la Vida’. Building into skittering electronica with searing guitars before running away into a surprisingly joyous chorus, this was proof alone that Coldplay's bold reinvention have given them plenty of life yet."
- Originally, the band intended to release "42" as the album's first single, but changed it later for "Violet Hill".