Zürich Opera House
(Op. 21), is an opera in three acts by Alexander von Zemlinsky to a libretto by the composer after the play "" by Klabund – a telling of the "Chalk Circle" story. The opera was written during 1930-31 and premiered on 14 October 1933 in the Zürich Opera House. Among the singers were Artūrs Cavara, Maria Madlen Madsen Maria Bernhard-Ulbrich; Fred Destal, Georg Oeggl and Peter Klein; it was directed by Karl Schmid-Bloß and the stage design was by .