She was a Swiss Opera soprano singer. Casa was known as one of the foremost interpreters of Richard Strauss. Throughout his career she sang at the major opera houses more than 200 performances like The Marriage of Figaro:Countess Almaviva, Don Giovanni:Donna Elvira, Die Meistersinger von Nürnberg:Eva, Der Rosenkavalier:Die Feldmarschallin, Octavian
Der Zigeunerbaron:Saffi, Arabella:Arabella, Ariadne auf Naxos:Ariadne, Lohengrin:Elsa, Madama Butterfly:Cio-Cio-San and La bohème:Mimi. She died on December 10, 2012 in Münsterlingen.