When a composer dies young, what is lost? Had Schubert reached the age of 50 rather than dying at 31, would we now have a much-expanded trove of his greatness? Bernard Holland isn’t so sure: “Life spans measured in years don’t take into account how fast we live them. Composing at the speed of life (forgive me), Schubert at 31 was like any normal musical genius at 65.”