During a performance of Beethoven's Fidelio at the Vienna State Opera there is an explosion in the foyer just off the auditorium. Auguste Rodin's famous 1909 bronze bust of composer/conductor Gustav Mahler has been blown up and a hate-filled note has been left at the scene demanding that there be "no more Jews defiling our culture." Retired art historian/musicologist Megan Crespi, in Vienna to lecture, is at the performance with her former student,...