This weekend the Salzburg Festival, the Arena di Verona, and the Edinburgh Festival  see their respective seasons come to an end. But before they end, there are still must see performances. Argentina  At the Teatro Colón, Kurt Weill’s “Rise and Fall of The City of Mahagonny” gets its second and third performances with Iris Vermillion and Alejandra Malvino alternating the role of Leokadja. Austria  The {…}