Now the band is taking fans behind the scenes of the making of Songs of Innocence - on Twitter. "These songs were always destined," Bono said in voiceover narration. "But rather than it being painting by numbers, where it's very disciplined and subscribed, it's coming together in a way that's even surprising for us."

The frontman continues, likening their artistic process to that of Eastern artists, who notably prefer to capture the spirit of something in a painting rather than its exact likeness.

"I always think of the zen artists, who spend all their time mixing the ink," Bono said. "Then it's that last few minutes, where the work, the actual gestures are recorded - that's the way our albums always go."