Mezzo-soprano Stephanie Tritchew appears as Rosina, singing with great warmth and luminosity, strength and centeredness. Rossini’s glorious Una voce poco fa (“The voice I heard just now”) is given gorgeous expression, but it is her tripping, double quick coloratura duet with Figaro, Dunque io son (“Then it is I”), that truly impresses. Together, Tritchew and Kirby dazzle.