"Rick Rubin has a larger looming presence on this album than his 'thank you' deserves. He asked 'Why can't more people cover U2 songs?' And it's because, with all the great sounds and arrangements, you can forget that there isn't a song there."
- Bono on Rubin's influence on Songs of Innocence
U2 have played nearly 1500 live shows all around the world which all told have consisted of over 20,000 various songs played in proper live shows, promotional dates and impromptu performances with many regions such as China yet to see a live U2 performance.