Originally set in Naples, Mozart’s Così fan tutte of 1790 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 they agree to a wager with him. They will pretend to be called away to war and then return disguised as Albanians to try...