The problems don’t stop there. Our encore is from the other side of the Atlantic—a zarzuela duet, “Caballero del alto plumero” from Moreno Torroba’s “Luisa Fernanda.” Here we hit a bigger snag, Castilian Spanish turns the “s” sound of words that contain “ce,” “ci,” and “z” into that familiar “th” we’ve all heard (and sometimes mocked). It’s second nature for “Cathtilians,” but it tends to drive Latino people around the bend. A phrase like “graciosa y dulce voz,” which ought to be sung “grathiosa y dulthe voth,” is likely to come out in a tangle of misplaced lisps and hisses, followed by an embarrassed smile as they catch my disapproving eye. I have faith that they’ll master it, but frankly who cares, when they sing the duet so brilliantly?