During World War II, the stage was destroyed by Allied bombs and the building gutted by fire on March 12, 1945. The foyer, with frescoes by M. v. Schwind, the main stairways, the vestibule and the tea room were spared. Almost the entire décor and props for more than 120 operas with around 150,000 costumes were destroyed. The State Opera was temporarily housed at the Theater an der Wien and at the Volksoper.
Gustav Mahler is one of the many illustrious conductors who have worked in Vienna. During his tenure, Mahler cultivated a new generation of singers, such as Anna Bahr-Mildenburg, Selma Kurz and Leo Slezak and recruited a stage designer who replaced the lavish historical stage décors for sparse stage scenery corresponding to modernistic, Jugendstil tastes. Mahler also introduced the practice of dimming the lighting in the theater during performances, which was initally not appreciate by the audience. However, Mahler´s reforms were maintained by his successors.
Other conductors at Vienna have included Hans Richter, Felix Weingartner, Richard Strauss, Clemens Krauss, Wilhelm Furtwängler, Bruno Walter, Karl Böhm, Herbert von Karajan, Lorin Maazel, Claudio Abbado, and Ricardo Muti
Until the directorship was taken over by von Karajan, Vienna maintained a permanent ensemble. Von Karajan introduced the policy of engaging guest singers.