Its songs are characterised by sparse elements such as simple chord progression, keyboard ostinatos, and fading motifs, while Smith's production incorporates both programmed beats and live percussion instruments.

The lyrics, written by guitarist Romy Madley Croft and bassist Oliver Sim, feature inner monologue and simple metaphors to explore a failing relationship and the emotional dynamics of a romance.

[3][6] After the departure of group member Baria Qureshi, the xx exclusively played live concerts throughout 2010, including several high-profile summer music festivals,[5] and garnered a growing fanbase.

[2] The band's producer and percussionist Jamie Smith pursued electronic dance styles on other musical projects,[7] creating remixes for Radiohead, Adele,[8] and Florence and the Machine.

[10] A novice to DJing when starting out with the xx, he subsequently learned its technical aspects and developed a grasp on controlling the crowd through unexpected silences and drops during his live sets.

"[11] Croft felt more expectations from listeners than when the band debuted and consequently turned to more personal songwriting for Coexist: I was sitting at home knowing people were going to hear us and what they were going to say.

[13] When he first read them, Smith found Croft and Sim's lyrics to be "purposely ambiguous so people can relate to them", saying in an interview for Uncut, "I mean... if I listen carefully, I do know about their lives intimately so I can guess what they're about.

He used Logic Pro recording software, a Space Echo effects unit, preamplifiers, and Casiotones on occasion,[15][17] as well as both synthesised steelpan sounds and live percussion instruments.

[14] The songs on Coexist, which Edna Gundersen of USA Today categorised as indie pop,[18] eschew melodic structure for minimalist dynamics and sparse sounds.

[19][20] John Calvert of Fact asserts that it is "a far more meditative album" for deviating from its predecessor's "tight, brisk pop songs", "nuanced [guitar] interplay", and "light dynamics".

[20] The songs are characterised by droning harmonies,[24] simple chord progression, keyboard ostinatos,[25] ringing guitar,[9] resounding reverb,[19] slight bass grooves, and programmed beats.

[9] Critic Will Hermes views Smith as a more prominent contributor on Coexist than on the debut album and comments that "the beats and musical backdrops are more varied and command more attention.

"[9] Stephen Thompson of NPR comments on the music's lack of dynamism, writing that the band "lets its songs billow out softly and quietly, with only achingly pretty guitar lines to lessen the tension.

"[34] Michael Hann of The Guardian writes that the album refines the band's "already skeletal frame" and that most of its songs are "defined as much by space as by sound", adding that the music's "gaps bring greater emphasis" to guitar, piano, and vocal elements.

"[24] Kevin Liedel of Slant Magazine felt that the songs follow-up on the "lovebirds" from the xx's debut album, "now separated and devastated ... mus[ing] on what went wrong".

"[23] Music journalist Luke Turner calls its subject matter more "turbulent, sensual and fun" than on the group's first album and states, "of course not necessarily a sexual or romantic one, the feel of this second record is far more earthy, sticky, complicated, like the tension of the second or third encounters after a one night stand.

[39] John Calvert of Fact asserts that it is a stark "conflation of urban and indie music", noting its "portomento [sic] synths and rumble-bass (think 'Drop It Like It's Hot') passing under tremolo guitar.

[39] Consequence of Sound's Harley Brown views that "Reunion" and "Sunset" make up a congruous mix at "the heart of the album", as Smith "indie-streams these house varieties ... slowing down and alienating beats from their context so they're even more universal, unobscured by their dance floor origins.

[39] "Tides" opens solely with Croft and Sim's vocals,[40] and features fading musical elements, including lock-step percussion, minor strings, an isolated guitar line,[32] and a wavy bassline.

[21] "Unfold" comprises individual notes and pauses,[42] and incorporates tension in its off-beat composition,[21] while its percussion increases in tempo before the accompanying instrumentation follows suit.

[11][44] Croft compared the mixture of oil and water to her holistic view of the band, saying in an interview for Grantland: You see a puddle of petrol on the floor – it can look sort of beautiful with the colors that come through it.

[70] Reviewing in October 2012 for Uncut, Garry Mulholland called the album a "masterpiece" of conceptually identical but "stronger, deeper, better" music when compared to the xx's debut.

[6] In Rolling Stone, Jody Rosen hailed the band as "masters of restraint",[25] while Chicago Tribune critic Greg Kot felt that the album "functions as a near-perfect mood piece" and, "because there are so few elements in each song," each sound "makes a bigger impact.

"[26] Writing for The Daily Telegraph, Neil McCormick praised Smith for "somehow widening and deepening the sound without intruding",[8] and Puja Patel from Spin credited him for "both stretching and magnifying the gritty beauty of his vocalists".

[35] In MSN Music, Robert Christgau applauded the group's preoccupation with "young love" and stated, "these scrupulously abstract verses capture its obsessive doubts and fragile exaltations with delicacy and tenderness.

"[73] Michael Alan Goldberg of The Village Voice called the album "gorgeous" and said that the music is like a "haiku instead of sonnet; Hemingway rather than Fitzgerald, with meaning and emotion lurking beneath the surface.

Andy Gill of The Independent believed that the band's songs had taken on "raging emotions" lacking on their debut and making Coexist a worthy but occasionally "uneasy listening".

[72] The New York Times critic Jon Caramanica said the record suffers from a difficult second half on what is otherwise "as insular and micro as ambitious pop music can be ... a wonderful experiment in the power of absence.

[43] Several critics and publications ranked Coexist as one of 2012's best albums in their year-end, top-ten lists, including Kitty Empire of The Observer, The Austin Chronicle, Les Inrockuptibles, State magazine, and The Guardian, whose staff voted it eighth.

[76][77] However, the magazine XLR8R ranked the album number seven on their list of the most overrated releases of the year, feeling that the trio's dark and minimal sound on the record was not as exciting as on their debut LP.