Unlike the case during World War I, Wagner’s works were performed throughout World War II in America as well as in the Third Reich. Hitler marketed Wagner’s operas as the artistic epitome of Nazi Germany, even though the composer had died in 1883, six years before Hitler was born. Beethoven was claimed by both the Allied and Axis powers. The opening of his Fifth Symphony became the musical motto of victory over the Germans who had claimed those very same four notes as another example of their über alles superiority. When the Bayreuth Festival — an event founded by Wagner...