Songs of Innocence is the thirteenth studio album by the Irish rock band U2, released on 9 September 2014. It was produced by Danger Mouse, with additional production from Paul Epworth, Ryan Tedder, Declan Gaffney, and Flood. After the surprise announcement of the album at an Apple product launch event, it was digitally released the same day to all iTunes Store customers at no cost. It was exclusive to iTunes, iTunes Radio, and Beats Music until 13 October 2014, when it was released to retailers by Island and Interscope Records. The digital release made the record available to more than 500 million iTunes customers, for what Apple's CEO Tim Cook called "the largest album release of all time". After the relatively low sales of U2's previous record, No Line on the Horizon, lead vocalist Bono expressed uncertainty about their relevance. Over five and a half years—the longest gap between U2 albums at that point—the group worked on projects with multiple producers, including Songs of Ascent, an aborted companion to their previous record. However, they struggled to complete an album to their satisfaction and continually delayed a release. From Wikipedia (https://en.wikipedia.org/wiki/Songs_o...) under Creative Commons Attribution CC-BY-SA 3.0 (https://creativecommons.org/licenses/...)