It's not what the xx put into their music. It's what they leave out. On their second LP, as on their 2009 debut, the Londoners are masters of restraint, building songs from simple chord progressions, delicate guitar and keyboard ostinatos, the gentle rub of Romy Madley-Croft and Oliver Sim's his-and-hers croons – and, most of all, from silence. The musical minimalism is matched by the lyrics. The songs are vignettes, about little things – a glance, a gesture, a murmured word – that mark big romantic sea changes. In "Tides," Madley-Croft and Sim sing, "You leave with the tide/And I can't stop you leaving/I can see it in your eyes/Some things have lost their meaning."

Coexist will not surprise old fans. The xx haven't altered their sound, they've refined it, adding a splash of arena-rock guitar here, a clubby 4/4 thump there. There are hints of Timbaland in "Chained" and Prince in "Tides." But, spiritually speaking, they're less funk than soul. Listen to Madley-Croft and Sim duetting on "Our Song": "When no one wants to/I will give you me/And we'll be/Us." They are the pasty English hipster Roberta Flack and Donny Hathaway – full of heart and, yes, even a bit of sexiness. For the xx, Coexist is a philosophy.

Listen to Coexist:

“Karma Chameleon”

Boy George has said this song was about standing by what you believe in. However, at the time, he was involved in a secret affair with Culture Club drummer Jon Moss. "Now people can understand the songs better," he said. "They were written about my relationship with Jon, and they were also written about being a gay man in a homophobic world." The lines "If I listen to your lies, would you say/I'm a man without conviction/I'm a man who doesn't know how to sell a contradiction," described his life at the time, he said. "I was selling this big lie."