The Mostly Mozart Festival has opened, with music director Louis Langree leading a gala concert. He is in his third summer with the festival, and he has proven an excellent choice for that post. On Thursday night, he had with him two soloists, one a superstar and the other a should-be superstar: Renee Fleming, soprano, and Stephen Hough, pianist.

Avery Fisher Hall was full, with people begging for tickets outside. PBS cameras were there for a live broadcast. This seemed as much a happening as a concert.

The hall itself looked different, boasting a reconfiguration. The stage jutted out into the audience; some patrons sat behind, and on the sides. Above were what appeared large throat lozenges – these were acoustical enhancers – and distinguished, oblong lamps. I can’t say what practical difference all this made, but it looked sort of neat.

Mr. Langree led the Festival Orchestra in a Whitman’s Sampler of a program, including a Mozart symphony – whose movements were broken up – and some J.C. Bach, and several other morsels. He had a theme for his program, as for the festival as a whole: “Mozart’s Travels.” And yet no theme – certainly no stated theme – is necessary: Good, intelligently arranged music is good enough.

The conductor began the evening with the first movement of Mozart’s Symphony No. 35 in D major, K. 385, the “Haffner.” He exhibited the qualities we’ve come to expect from him: incisiveness, clarity, gracefulness, verve. As with most Langree performances, the orchestra seemed well prepared, ready to perform. This should be taken for granted; it cannot be. Furthermore, Mr. Langree conducted as though he likes music. But don’t they all? Sadly, no.

He then took a microphone to talk to the audience, which I consider a bane of the concert scene, although I’m glad to report that Mr. Langree spoke fairly charmingly. He gave sort of an apology for the program, saying that such a lineup would have been common in Mozart’s time. Whatever. Just play. (I grant that Mr. Langree might have needed to fill some television time as stagehands did their work.)

Next, Renee Fleming sang three Handel arias, looking more like America’s other Sweetheart, Katie Couric, than ever (Miss Fleming herself, not the Handel arias).The first of the arias was “Endless pleasure” (which happens to be the title of a Ruth Ann Swenson Handel-and-Mozart CD, but that’s another matter). In general, I am a defender of Miss Fleming’s Handel singing, but sometimes she can be hard to defend – as she was on this occasion. Her first F was flat, and her second was sharp. But the main problem was extreme rubato, extreme license, a self-indulgence. She slid and slopped around, spoiling the shape and effect of the aria. It was almost vulgar.

The second aria, “O sleep, why dost thou leave me?” was little better. It was beautiful, in a way – Miss Fleming can’t help being that – but it was harmfully soupy: You would hesitate to play a Chopin prelude in this fashion.

Rounding out the group was “Let the bright seraphim,” that sparkling, affirming aria for soprano and trumpet. You could tell, as the orchestra was playing the opening measures, that Miss Fleming was looking forward to singing the piece, and she sang it decently, despite some flatness. Outstanding in this aria was the trumpeter, Neil Balm, who was as smooth and characterful as you could want. As for the soprano, this evening did not represent what she can do in Handel. You should have heard her Rodelinda at the Met last season.

The orchestra continued with the second movement of the “Haffner” Symphony, which featured a clumsy entrance, some further raggedness, and a crying baby. Far better was a movement from J.C. Bach’s Sinfonia in G minor, which was lively, taut, and engaged. Breathing through it was Mr. Langree’s sense of balance.

Then came Stephen Hough, to play the slow movement of Mozart’s Piano Concerto No. 23 in A major, K. 488.This Adagio is an F-sharp-minor beauty, and Mr. Hough rendered it superbly. Every note was true, bearing its proper weight, having its place in the movement at large. One had the impression of perfect calibration. It was the kind of playing that recalls Lipatti, Haskil, Kraus. And blessedly, Mr. Hough was not too slow – an overslowness ruining one Mozart “slow” movement after another.

As the orchestra sat, he next played three little pieces of Rameau. Mr. Hough is a supervirtuoso, yet you will seldom hear the French Baroque so well expressed. In this, he reminded me of an earlier supervirtuoso, Georges Cziffra, who loved the French Baroque, including Rameau, along with his Liszt. What you got from Cziffra, you get from Mr. Hough: exquisite taste.

Out again came Renee Fleming, to sing Mozart’s concert aria “Bella mia fiamma … Resta, o cara.” In the beginning of her career, this soprano sang a lot of Mozart, and she has never let it go.On Thursday night, she was at her Mozartean best: The voice was beautiful (of course), the technique secure, the musical conception pure. She was the queen of the high piano; and that lower register was meaty, mezzo-y. To all these virtues we might add an exemplary diction. When she sings like this, Renee Fleming is not hard at all to defend.

Mr. Langree closed his program with the final two movements of the “Haffner” (for it would have been strange to isolate the third movement, the Menuetto). How’d they do? Well enough, but I will have more to say about Mr. Langree, the Mostly Mozart Festival Orchestra, and the “Haffner” Symphony later in the week, as these forces will play it – without interruption – in their second concert of the season, on Tuesday night.

The encore? I was thinking the overture to “The Marriage of Figaro.” But no: Mr. Langree and the orchestra tucked back into the finale of the “Haffner,” thereby presenting a true encore (which initially meant playing the same thing again, not something else in addition). This was a wise choice: That Presto – that shout of D-major joy – fairly demands to be played more than once.

***

In the above review, I mentioned supervirtuosos: Marc-Andre Hamelin, the Canadian pianist, is one. And he gave a recital on Saturday night at the Mannes College of Music. This was the last big recital in the school’s International Keyboard Institute & Festival, founded and directed by the pianist and teacher Jerome Rose.

Earlier this summer, Mr. Hamelin played the devil out of Liszt’s “Totentanz,” with the New York Philharmonic. And he played much devilish, supervirtuosic music in his Mannes recital. But he began with Schubert’s “little A major” sonata, Op. 120, the one associated with Myra Hess and other poetic pianists. He was loose with rhythm and interpretation right off the bat. Would it not have been better to begin relatively straight, saving the freelancing, the personalization, for the repeat? Sometimes you prove your sensitivity by letting music alone.

Later on, Mr. Hamelin’s octaves were way too big for this little piece, wrecking his balance. Those octaves were poorly executed, too, which was strange from this technical magician. The second movement, however, was appropriately dreamy and nostalgic, and it also had a solidity, avoiding wispiness. Here again, Mr. Hamelin was a little loose for my taste, but he was well within bounds.

The closing Allegro started out limpid, gay, and lovely – very pianistic. Mr. Hamelin did not maintain that standard, however. His playing got awkward, a little thick, and there was again some pounding in octaves. Nevertheless, Mr. Hamelin gave a respectable account of this small masterpiece.

Then he did something really special: He played nine of Leopold Godowsky’s “Studies After Chopin’s Etudes.” Godowsky was one of the great pianists of the first half of the 20th century, and one of the greatest pianists in history. Unfortunately, he abhorred making records, and is said not to have recorded well. And the number of people who heard him in the flesh is dwindling. “That line,” they say. “You’ve never heard a musical line played like that.” Anyway, Godowsky composed, transcribed, and otherwise fiddled with many pieces, and he did delicious things with Chopin’s Etudes. You hear some of the original in each “study,” but you also hear a good deal of Godowsky.

Mr. Hamelin played these pieces as expected: with technical mastery and musical sympathy. He was not immaculate, however; some of his playing was labored. And he did not wring the last musical drop out of these pieces. He could have done more with dynamics, with climaxes, with the arc of a piece. But he played well enough, and those studies for the left hand alone were especially impressive. Smartly, he ended with Godowsky’s first study – that after Chopin’s majestic, dizzying C-major etude, Op. 10, No. 1.

And hats off to Mr. Hamelin for resurrecting this wonderful, and super-pianistic, repertory. It was especially pleasing that Mannes’s students were exposed to Godowsky, who should not be forgotten: either as pianist or as composer-arranger.

This recital’s intermission was absurdly long – longer than the Met’s at their worst – and when Mr. Hamelin returned, he played three transcriptions of Liszt. The first was that of Wagner’s “Liebestod,” and if there is a trashier piece in the piano repertory, I don’t know it. I have heard it played as well as possible: by Horowitz, by Jean-Yves Thibaudet. And, in my view, nothing can rescue it. Those tremolos repulse you every time. Never in history has more damage been done to so great a piece of music. That said, Mr. Hamelin did as much with it as he could.

He went on to two marginally better pieces: Liszt’s “Ernani” Paraphrase (after the opera of Verdi) and his “Norma” Reminiscences (after the Bellini opera). Always, Mr. Hamelin displayed dignity, and a knack for bringing out the melody amid a blizzard of notes. He is a phenom, Marc-Andre Hamelin, and a musician.