Bono and Edge have been speaking to Rolling Stone after a  survey by digital-data research firm Kantar found that almost one-fourth of music users on iOS devices listened to at least one U2 song in January 2015.  The band were the most-listened to artist during the period of the study.

Nearly all of those users, 95 percent, listened to at least one song from Songs of Innocence, the album released on iTunes straight to iOS users' mobile devices in September.  According to Kantar, which sampled 978 iOS users drawn from a larger panel of more than 2,500, 23 percent of them listened to U2 in January. In comparison, 11 percent listened to at least one song by Taylor Swift.

Rolling Stone asked Edge what the band have learned about music in the digital era - the value people put on it and how they listen to it - following the release of Songs of Innocence.

'We're in the dawn of it. The thing it's easy to forget when you live in modern times is that they're modern for about another 30 seconds. . . more so than ever. In a few years we'll look back on this time like we look back on VCRs and rotary phones. When the radio arrived, everyone thought that was the end of sheet music.
'I think music has become devalued and disposable in the commercial world – but not to music lovers or the people who make it, and not all big tech either. Apple – and U2 – fight hard for artists to be paid. In the future, technology has to be a better servant of music, and not its slave master. We can take advantage of the benefits of technology, and we do, but it's also beholden on those of us who have been so well rewarded by music to figure out a way to preserve the ability for artists to create and thrive.'

Both Bono and Edge were interviewed on email for Rolling Stone. Read the whole story here.