Music: Isolde at La Scala

Neither Kirsten Flagstad nor the Italian cops knew what to expect. In Milan last week 200 plainclothesmen were sprinkled through the audience in famed La Scala opera house, and outside, strong police squads stood ready. There had been hints of trouble. The former chief of staff of the Milanese partisan organization demanded that the performance of Tristan und Isolde be canceled. He objected not to Soprano Flagstad's much-criticized war reputation—but to the fact that the opera would be sung in German.

It was Kirsten Flagstad's first appearance in opera since the war and she was nervous. She had been widely attacked because...