魔笛
His research has received international attention owing to the discovery of new attributions to Mozart in Emanuel Schikaneder's collaborative opera "Der Stein der Weisen oder Die Zauberinsel" (Vienna, 1790). His study of the theatrical tradition in which Mozart's "The Magic Flute" originated has led him to new interpretations of the libretto, notably skepticism to the widely held view that "The Magic Flute" is specifically a Masonic opera (see Libretto of The Magic Flute).