There have been many fine performances of “Un Ballo in Maschera” by Giuseppe Verdi in New York during the past 50 years, but my favorite has to be the version offered in 2000 by the New York Grand Opera in Central Park. It rained so hard that evening that maestro Vincent La Selva had to cancel the third act, sparing our hero Riccardo from being murdered and sending us all home happy.

In the current run that began on Monday evening, the Metropolitan Opera not only kills off Riccardo, but calls him Gustavus, returning to the original Swedish setting of the drama that the censors forced Verdi to abandon for — of all places — Puritan Boston, when a European regicide hit a little too close to home in the turbulent 1850s.

The evening got off to a literal slow start as Gianandrea Noseda, who otherwise conducted a very animated and propulsive rendition, elongated the tempo in the first scene to accommodate his Oscar, the soprano Ofelia Sala, who was making her Met debut. Sadly, Ms. Sala could not handle her alliterative diction even at this remedial speed, and her maiden voyage was more of a shakeout cruise. But after this initial bout of messiness, the remainder of the evening bore witness to a good, if uneven, ensemble performance.

Although this was not announced from the management, the rumor was rampant in the house that tenor Salvatore Licitra was suffering from a bad cold. This seems as good a reason as any for his subpar performance. In that lamentable first scene, he found himself gasping for breath and swallowing many phrases in order to keep up. This is certainly not his big-voiced habit and although he took it easy, he was never able to confidently stand and deliver up to his personal standards.

The other principals were fine. Michèle Crider was a vocally poised Amelia, demonstrating tremendous improvement over her Carnegie Hall performance in 2004. Her big scene at the gallows in Act II was secure and completely in pitch, including the difficult high C just before the entrance of her husband Renato — oops, I mean Count Anckarström.

She did not, however, endow her character with much passion, and even her “Morro, ma prima in grazia,” one of the most emotionally laden arias in all of Verdi, was delivered technically correctly, but somewhat colorlessly. This lack of characterization was immediately exposed because Verdi’s masterstroke is to follow Amelia’s aria with the most complex singing of her husband. Dmitri Hvorostovsky was not only in splendid voice but performed a superb “Eri tu,” a famously difficult recitative and aria that explores the inner dimensions and drives of his character in a manner reminiscent of Iago’s “Credo” in the “Otello” to come. Not only did Mr. Hvorostovsky offer a finely tuned, exquisitely colored, and subtly balanced account of this set piece, he had the confidence to crack his voice on purpose at its end, emphasizing the depth of his emotions. This was a masterful combination of the singer’s and the actor’s art.

And he might not have even been the best in the cast. Stephanie Blythe had only one scene as Ulrica the fortune-teller to make it happen, but she scored with a stunning display. Stepping out of a giant suspended pentagram, Ms. Blythe sounded as if she were from a different species entirely, an otherworldly creature possessed of unspeakable knowledge.

She plunged headlong into the depths of her voice with no transition or warm-up. The actors looked at her in awe because that is their direction; the audience members had the same reaction on their own.

The opera demands a rather deep suspension of disbelief from its audience. After all, what would have ever possessed Amelia to want to leave Mr. Hvorostovsky for Mr. Licitra in the first place?