It may be difficult to imagine today, but Arturo Toscanini--recognized widely as the most celebrated conductor of the twentieth century--was once one of the most famous people in the world. Like Einstein in science or Picasso in art, Toscanini (1867-1957) transcended his own field, becoming a figure of such renown that it was often impossible not to see some mention of the maestro in the daily headlines. Acclaimed music historian Harvey Sachs...