I have never understood what people meant by saying “the music was so witty” but Così has given me an idea. Take the overture: it begins with lordly violins that correspond to the men’s pompous certainty about their women’s faithfulness; then come the sinuous feminine notes of the English horn. The two call and respond to one another in a way that anticipates the back and forth of the love plot. As the overture ends the music slows and we hear five notes match the five syllables of the title: Co-sì fan tu-te, the warning words that Don Alfonso sings to the same tune in the last scene. Whenever the theme was played, I imagined the old man wagging his finger wearily.
Hmm. Perhaps the writer means French horn?! I’ve played the opera a number of times. I can assure you there is no English horn in it!
I read it here.