Così fan tutte of 1790 is the third and final opera (after Le nozze di Figaro and Don Giovanni) on which Mozart collaborated with the librettist Lorenzo Da Ponte. Originally set in Naples, it sees the philosopher Don Alfonso challenge two soldiers, Ferrando and Guglielmo, to prove that their respective fiancées, the sisters Dorabella and Fiordiligi, are faithful. He is certain that no woman ever is, but the younger men are so convinced of their own lovers’ fidelity that...