On the evening of April 26, 2019, guests excitedly filed into the Metropolitan Opera’s grand auditorium, eager to experience Verdi’s masterpiece “Rigoletto.” Returning to the stage for its second run of performances this season with a new principal cast, Michael Mayer’s production sets the tragic opera in Las Vegas in the 1960s. With the audience seated and Maestro Nicola Luisotti standing ready {…}