U2 in Las Vegas

"If we’re going to make an album, it’s very important to us that every song on the album is a '10'. I think the reason people aren’t buying albums is a lot of times they only get one or two good songs. For us, every song had to be extraordinary, and special, and unique, and the whole had to be better than the sum of its parts. You’ll have to decide if we achieved that, but that’s what we were attempting." - Bono, 2009