“I was working with Larry Mullen, Jr., on one of the U2 albums,” [Brian] Eno told me. “ ‘All That You Don’t Leave Behind,’ or whatever it’s called.” Mullen was playing drums over a recording of the band and a click track—a computer-generated beat that was meant to keep all the overdubbed parts in synch. In this case, however, Mullen thought that the click track was slightly off: it was a fraction of a beat behind the rest of the band. “I said, ‘No, that can’t be so, Larry,’ ” Eno recalled. “ ‘We’ve all worked to that track, so it must be right.’ But he said, ‘Sorry, I just can’t play to it.’ ”

Eno eventually adjusted the click to Mullen’s satisfaction, but he was just humoring him. It was only later, after the drummer had left, that Eno checked the original track again and realized that Mullen was right: the click was off by six milliseconds. “The thing is,” Eno told me, “when we were adjusting it I once had it two milliseconds to the wrong side of the beat, and he said, ‘No, you’ve got to come back a bit.’ Which I think is absolutely staggering.”