Operas are frequently derided for their weak plots. Many are based on melodramatic plays or novels that were once popular but have failed to stand the test of time. Franco Alfano’s Cyrano de Bergerac is a welcome exception. Alfano’s opera lacks musical originality, but it has both depth of emotion and great respect for Rostand’s theatrical masterpiece. It helps that Henri Cain’s libretto is more or less a shortened version of the play. While speeches and...