U2 in San Francisco

"I think to be in a studio, tied to the four-piece band setup right now is a very modern thing to do. And to use that mystery and power to write songs, we did two records like that. This one goes even further than the last one in that direction. You get beauty like Original of the Species that you can play on a piano. Just put piano and voice on that song, and it's special. That's not retreat. That is progressive. That is progress." - Bono, 2005