In this Nov. 5, 2012, photo provided by the Metropolitan Opera, Verdi's “A Masked Ball” is performed by, from left, Marcelo Álvarez as Gustavo III, Kathleen Kim as Oscar, and Dmitri Hvorostovsky as ... more 

In this Nov. 5, 2012, photo provided by the Metropolitan Opera, Verdi's “A Masked Ball” is performed by, from left, Marcelo Álvarez as Gustavo III, Kathleen Kim as Oscar, and Dmitri Hvorostovsky as Count Anckarström during a dress rehearsal at the Metropolitan Opera in New York. (AP Photo/Ken Howard) less