 Among the productions during his tenure were the world premiere of Weill's "Die Bürgschaft" in 1932, and a new production of Verdi's "Un ballo in maschera" in the same year, on which he collaborated for the first time with the conductor Fritz Busch.When the Nazis came to power in 1933, Hermann Göring, in his capacity as chief minister of Prussia, offered Ebert an expanded role, with control of all the opera houses of Berlin.Ebert, politically hostile to Nazism, preferred instead to leave the country and base himself and his family in Switzerland, where he rented a home in Lugano.