This morning, right after the 8 o’clock news, we heard a symphony by an Italian who became court composer to Austria’s Joseph II in 1774. By the time 25-year-old Wolfgang Mozart moved to Vienna, our mystery author, six years Mozart’s senior, was considered an authority of musical taste. Both the play and the movie, “Amadeus”, would have us believe he was a wrathful schemer who poisoned Mozart. Who is he?