You've probably heard the famous story of how the Everly Brothers broke up mid-concert at a 1973 show at California's Knott's Berry Farm, but what I didn't know about that until very recently (i.e., last night) was that the break-up was a bit wind-aided. Phil and Don were thoroughly sick of each other long before that final snap, and indeed had already decided to break up the act, but they had a contract for that three-night stand at Knott's Berry Farm that they had to fulfill.
Don showed up for the final show drunk, and stumbled through lyrics and harmonies for about five songs before Phil had had enough. He smashed his guitar on the stage and walked off, saying only, "I quit." (Playing such a Spinal Tap-ish venue couldn't have helped matters.) But if he hadn't quit that night, they were planning to quit on each other the next day.