If you’ll pardon the celebrity-world language, Anna Netrebko and Rolando Villazon are probably the hottest singers in opera.They appeared in Verdi’s “Rigoletto” at the Metropolitan Opera on Saturday night. She is a Russian soprano, and he is a Mexican tenor.They are paired together in opera houses around the world, in such operas as “Romeo et Juliette” (Gounod) and “La Traviata” (Verdi again). Last summer at the Salzburg Festival, they sang in this latter opera, and caused a sensation. They were virtually the talk of the Continent.

It does them no harm that they are young – youngish – and good-looking. This is opera, after all. In that “Traviata,” the stage director Willy Decker had them rolling around like minks, and he couldn’t be faulted.

Let it be said straight away that Miss Netrebko was not at her best on Saturday night. Her portrayal of Gilda had dramatic poignancy, of course, for Miss Netrebko is a powerful singing actress – often a gripping one. But it was plain from her first notes that something was wrong with her, vocally. Her sound was pillowy, unclear, and she didn’t have control of her technique. Her pitch was errant,and her top was harsh.Moments in the aria “Caro nome” were painful to listen to.And I had the thought that she may be too imperious for the role of Gilda, considering that girl’s sweetness and purity.

But in Act II, Miss Netrebko was more herself, doing some admirable singing, even if she ended that act with a high E flat that was maybe 85 miles low. And in Act III, she had very few problems – concluding a rough night with honor.

Mr. Villazon had a good and confident night. He may be a tad underpowered for the Metropolitan Opera House, but he has a great many gifts. He sings easily and vibrantly, and he moves about the stage effortlessly. A protege of Placido Domingo, he embodies a Latin vocal style. I’m afraid he swoons around a bit, instead of traveling directly to the notes. His sound is not especially Italianate, and neither is his execution.

The tenor in this opera – i.e., the Duke of Mantua – has three great arias, and we’ll consider each, briefly. I have suggested that Mr. Villazon was slightly underpowered, but “Questa o quella” was too big, too heavy, in feeling – not light enough, not crisp enough, not graceful enough. The next aria,”Parmi veder le lagrime,” is one of the hardest in the tenor repertory. (The late Alfredo Kraus used to sing it every day, to keep himself in shape.) Mr. Villazon negotiated it very well. As for the famous “La donna e mobile,” Mr. Villazon was a little soupy in it,taking long breaths,running phrases together in an unexpected way. But those high notes were fairly ringing.

In the title role – Rigoletto – was an Italian baritone, Carlo Guelfi, who in “Otello” (Verdi) last season made a huge impression as Iago. (This was also at the Met.) He made a similar impression as Rigoletto. Mr. Guelfi can do just about whatever he wants, vocally, and he has the true Italian style – this is not so much a question of nationality as of other things (to be discussed another day, perhaps). And theatrically speaking, he portrayed Rigoletto convincingly. He did not play him too broadly, but he did not skimp on emotion, either. Rigoletto’s disintegration was heartrending.

Carlo Guelfi is not quite a big name, but maybe he should be.

Other singers in the Met cast handled their roles ably.The bass Eric Halfvarson made a rich and velvety Sparafucile, the killer-for-hire. His lowest note could be heard throughout the house – and probably in Lincoln Center Plaza as well. The baritone Brian Davis sounded elegant and virile as Marullo. The veteran bass-baritone James Courtney was tremulous and formidable as Monterone. And the mezzosoprano Nancy Fabiola Herrera made a smoky and sexy Maddalena.

Having a very good night was the conductor, Asher Fisch, an Israeli who works extensively in opera. In my experience, he is an uneven conductor, including on a single evening. But he was nothing but satisfying on Saturday night. The orchestra was responsive to him, and Verdi’s score was both nuanced and bold, as required. Just a couple of specifics: The end of Act I had huge, uncanny suspense. And when Rigoletto sang his bitter, raging “Cortigiani, vil razza dannata,” the orchestra played with what I can only call tormented brio – just right.

A third specific: The storm music in Act III is often sort of vaudevillian. But it was compelling under Mr. Fisch.

Along with that orchestra, the Met chorus performed well, and its men were notably agile in Act I, Scene 2.

The production is Otto Schenk’s from 1989, and, though entirely praiseworthy, it is quite dark – I mean, literally dark, not just dramatically or psychologically dark. I’m always complaining that I can’t see anyone. But then, the opera’s characters are always saying how dark it is, how they themselves can’t see anything – so who am I to complain?

***

Up from the Met at Columbia University, Miller Theatre presented a chamber concert, titled “Sextets & Septets.” (This concert took place on Friday night.) A perfectly serviceable title – although I might have been tempted to dub the evening “At Sixes and Sevens.” A group of disparate but cooperative musicians played four works, ranging from the early Baroque to today.They played them in an engaging, sensible order – not chronological order, but earliest, most recent; early again – and late Strauss.

This program promised an interesting listening experience. For one thing, you don’t often get to hear sextets and septets – or octets and nonets – on chamber concerts. You ordinarily have trios, quartets, and quintets. Although this has been a good little stretch for chamber works requiring more than five: In Zankel Hall last week, the St. Luke’s Chamber Ensemble played the mighty, glorious Beethoven Septet.

The Miller Theatre musicians were all string players, and prominent among them were Jennifer Frautschi, violin; Misha Amory, viola; and Fred Sherry, cello. First on the program were three fantasias by Orlando Gibbons, the masterly English composer of the early 17th century. And you thought he wrote only choral music? These fantasias come under the heading “Consort Music a 6.”

Friday evening’s sextet bobbled some notes, but the main problem was their sound: There was no need to be so wan, so sickly, so pained. This was a scratch- and whine-fest. Do people suppose that anything else is inauthentically Baroque? Throughout the Gibbons pieces, these players were determined to avoid beauty.The last piece is in a joyful G major, but you couldn’t tell that: Joy was largely suppressed.

I don’t know about you, but I rue the day when Baroque – at least early Baroque – came to mean tonal ugliness.

The musicians then turned to the String Sextet of Charles Wuorinen, composed in 1989. Immediately, the players were more musical than they had been in the Gibbons, more alert to one another, more convincing: They played as though they cared about the music. Mr. Sherry, in particular, takes amazing, visible pleasure in his work. Sometimes – especially in the most troublesome music – you have to envy him.

Mr. Wuorinen’s sextet is in one movement, and consists of vigorous, emphatic dissonances. Rhythm is inventive and snappy.And repetition is not exactly shunned.I am told by knowledgeable musicians – including composers – that Mr. Wuorinen is a genius. Some of us have to go on trust.To me, often, Mr. Wuorinen seems engaged in some private mathematics.

Do you know this story about Schonberg? He’s presiding over a concert-lecture, which begins with some piece of his – he will speak afterward. When the music ends, the critic Lionel Abel calls out, “Okay, Arnold, we’ve had the lecture – when do we get the music?”

At Miller Theatre, Mr. Wuorinen was on hand to receive the ovation of the enthusiastic audience.

After intermission, the musicians played some Bach,his Ricercar a 6 from the “Musical Offering.” Talk about mathematics – Bach’s piece is a scientific feat, a king of fugues. The musicians onstage (seven, incidentally, where you might have expected six) did not convey its complete greatness, however. They seemed to be reading through the music, without feeling it, without being … well, musical. They seemed much less involved than in the Wuorinen, into which they’d tucked lustily.

But there was some good playing to be heard, including that of Sophie Shao, who made a warm, bold sound on her cello.

To end the evening was that late Strauss, his “Metamorphosen,” from 1945 (the same year – the same period – in which he greeted American soldiers on his doorstep with the words, “I am Doktor Richard Strauss, composer of ‘Salome’ and ‘Der Rosenkavalier'”). This piece is an elegiac, transporting work, composed in ashes, essentially. Miller Theatre’s program notes provided a quote that is classic Strauss. The burning of the Munich Court Theater, he said, “was the greatest catastrophe of my life.There is no possible consolation.” Yup – that, for Strauss, was the tragedy of 1939-45: the loss of that theater.

In any case, “Metamorphosen” is a considerable achievement, and our seven musicians played it well.They made beautiful sounds, and they gave the impression of taking us on a journey. In my view, there should have been greater dynamic variation in the middle section, and the final section was short on otherworldliness.The C-minor ending can be much spookier, more chilling. But this little orchestra did credit to one of the old bastard’s most affecting pieces.

And we had had an unusual and basically satisfying evening of music.

“Rigoletto” will be performed again December 13 & 17, January 28, February 1, 8, 11, 15 & 18, and May 1, 4 & 9 at the Metropolitan Opera House (Lincoln Center, 212-362-6000).