Singers Ileana Tonca, Elisabeth Kulman and Michaela Selinger (L-R) perform as Wogllinde, Flosshilde and Wellgunde during a dress rehearsal of Richard Wagner's opera "Das Rheingold" on stage of Vienna's state opera April 29, 2009. The opera is conducted by Franz Welser-Moest and directed by Sven-Eric Bechtolf and will premiere on May 2. REUTERS/Herwig Prammer (AUSTRIA ENTERTAINMENT)