Their music employs soft echoed guitar, prominent bass, light electronic beats and ambient soundscape backgrounds.

Working with producer Rodaidh McDonald, the band released their debut album, xx, in August 2009.

[2][6] The band members met while studying at Elliott School, the same school attended by Hot Chip, Burial, Four Tet, actor Pierce Brosnan, Fleetwood Mac founder Peter Green and singer Matt Monro.

[4][13] In the 2009 NME The Future 50 list, the xx was positioned at number six, and in October 2009, it was named one of MTV Iggy's "Top 10 Bands with Buzz" (at the CMJ Music Marathon 2009).

[citation needed] In January 2010, Matt Groening chose the band to play at the All Tomorrow's Parties festival which he curated in Minehead, England.

In addition, the band played at five music festivals in the United States, Coachella, Sasquatch, Bonnaroo, Lollapalooza and Austin City Limits.

"[20][21] The music of its debut album was used extensively on television and in the media, such as 24/7, Person of Interest, NBC's coverage of the 2010 Winter Olympic Games;[22] during the series Cold Case, Suits, Mercy, the Greek version of Next Top Model, Bedlam, Hung, 90210, as well as being the feature song for the March 2010 E4 advert for 90210, Misfits, the Karl Lagerfeld fall/winter 2011 fashion show, Waterloo Road, and the film I Am Number Four.

"[27] In another promotional initiative, the label sent out Saam Farahmand's audio/visual sculpture of the album when the band toured at Bestival 2010, as well as to an event at Seoul.

[30] In December 2011, Smith revealed that he wanted to release the xx's second album ahead of its festival appearances the following year, and that it was inspired by "club music".

[36] In 2013, the xx held a series of three festival-style concerts, called "Night + Day", in Berlin, Lisbon, and London.

The festivals featured performances and DJ sets curated by the band, including Kindness and Mount Kimbie.

The band was nominated for a Brit Award for Best British Group, eventually losing out to Mumford & Sons.

[37] In April 2013, the xx contributed the song "Together" to the official soundtrack to Baz Luhrmann's adaptation of The Great Gatsby.

[38] In March 2014, the xx performed a series of shows at the Park Avenue Armory in New York City.

On 25 November 2016 the band announced an extended residency at the O2 Academy, Brixton – adding four additional days to their original tour and setting the record for longest run of sold-out shows in the venue's history.

[46] Madley Croft's debut solo album Mid Air, produced by Stuart Price, Fred Again, and Jamie xx, was released on 8 September 2023 through Young.

Madley Croft said: "Jamie started out very much into soul and then from there moved into hip-hop and UK-based dance music.

"[58] She also had mentioned her liking for Jimi Hendrix, The Slits, Joy Division, Yazoo, Eurythmics and New Order.

[60] Sim is an avid fan of Aaliyah, with the band covering her song "Hot Like Fire",[61] while Madley Croft enjoys Mariah Carey's music.