“La Scala serves not only as the universal drawing-room for all the society of Milan,” said Mary Shelley in 1840, after an evening at the fabled opera house, “but every sort of trading transaction, from horse-dealing to stock-jobbing, is carried on in the pit; so that brief and far between are the snatches of melody one can catch.” Explore the social life of La Scala through the colorful personalities that passed through its balconies over three centuries. —J.V.