Some respected sources (including Kutsch, K.J. & Riemens, Leo: 'Grosses Sängerlexicon', Franke Verlag, Bern and Stuttgart, 1987 Edition, Page 2697 - which further fails to mention that she ever sang in Paganini) claim that she also appeared with Tauber in Lehar's Der Zarewitsch, but this is incorrect. The 1927 operetta has only two soprano singing roles; one an ingénue role, played originally by de:Rita Georg, and the other a soubrette part, played by Charlotte Ander. There is simply no part in this operetta for a singer of Schwarz's voice and stature.