This weekend will be filled with new productions, an opening night in Zurich and, as always, many great stars. Austria  Olga Peretyatko-Mariotti headlines “La Traviata” at the Vienna State Opera with Jean-François Borras and Paolo Rumetz. At the Volksoper, “Die Zauberflöte,” “Gypsy” and “Il Barbiere di Siviglia” will be shown this weekend. Belgium  Anna Caterina Antonacci will sing her signature {…}