When you discover your bride-to-be in another man's bed on the eve of your wedding day, the excuse "Darling, I must have been sleepwalking" rates somewhere near the same level of credibility as "Sir, the dog ate my homework." But hey, this is opera, and bel canto opera at that. You didn't come to Bellini's La Sonnambula for the story and the drama: you came here for the singing.
I once heard a lecture by Gérard Mortier, then head of the Paris Opera, contrasting the twin operatic traditions starting from Monteverdi's serious and affecting dramma per musica and the lavish court entertainments of Lully. A couple of centuries on, there's no need to ask the side of the fence on which Massenet's Cendrillon falls.
