No Line on the Horizon is the twelfth studio album by rock band U2. Released on 27 February 2009, it was the band's first record since How to Dismantle an Atomic Bomb (2004), marking the longest gap between studio albums of U2's career. The band originally intended to release the songs as two EPs, but later combined the material. Photographer Anton Corbijn shot a companion film, Linear, which was released alongside the album and included with several special editions. U2 began work on the album in 2006 with record producer Rick Rubin, but shelved most of the material from those sessions. From May 2007 to December 2008, the band collaborated with Brian Eno and Daniel Lanois, who produced and co-wrote many of the new songs. Writing and recording took place in the United States, United Kingdom, Ireland and Morocco. The group intended to release No Line on the Horizon in November 2008; after composing 50 to 60 songs, they postponed the release because they wanted to continue writing. Prior to release, U2 indicated that Eno's and Lanois' involvement, as well as the band's time in Fez, Morocco, had resulted in a more experimental record than their previous two albums; the band compared the shift in style to that seen between The Joshua Tree (1987) and Achtung Baby (1991). Upon its release, No Line on the Horizon received generally favourable reviews, although many critics noted that it was not as experimental as previously suggested. The album was not as commercially successful as anticipated, and the band expressed disappointment over the relatively low sales, compared to previous albums, of five million copies. U2 supported the album with the U2 360° Tour, which became the highest-grossing tour of all time.