Faulkner and Becker, sociologists and experienced musicians, wrote a book about their musical experiences—Do You Know? The Jazz Repertoire in Action—describing how musicians who didn't know each other could perform competently and interestingly without rehearsing, or playing from written music. When they wrote it, they lived at opposite ends of the country: Faulkner in Massachusetts, Becker in San Francisco. Instead of sitting around talking about their ideas, they wrote e-mails. So every ...