VIENNA – It was 1947 in post-war Vienna, and Hilde Zadek remembers taking a deep breath behind the curtain. A rookie on her first opera gig, she was about to sing the prestigious role of Aida for an audience full of particularly harsh critics — whistle-packing Nazis she says were determined to show “that Jew from Palestine” she was not welcome at one of the world’s greatest opera houses

But their whistles stayed silent, as Zadek celebrated her first on-stage triumph.