For years, we critics had Kurt Masur to kick around here in New York. Many of us detected a certain air of kapellmeisterism about his performances. They were solid enough interpretively, but predictable, pedestrian. Although I could always count on hearing a decent realization of the repertoire, my suspicion that none of those evenings would turn out to be memorable has proved true.

Daniel Barenboim is the polar opposite. As a conductor, he is capable of flashes of brilliance, yet also prone to uninvolved, unfocused nights. For example, when he brought his Berlin Staatskapelle Orchestra to Carnegie Hall in 2000 for a six-concert series exploring Beethoven’s symphonies and piano concertos, he provided a superb Fifth Symphony and a revelatory Eighth. But other nights were sloppy and dull. The most bizarre evenings with Mr. Barenboim are those where both Dr. Jekyll and Mr. Hyde show up.

On Saturday night at Carnegie Hall, Mr. Barenboim teamed up with Radu Lupu, a pianist whom I have both loved and hated. They put on – what else? – an all-Mozart program. It appeared that my lowest expectations were justified when the first note of the Symphony No. 39 was enunciated in about eight different parts. But the Staatskapelle players merely needed some time to get accustomed to Mr. Barenboim’s beat: They made a smooth recovery and proceeded to create a thoroughly modern sound for this late work.

Mr. Barenboim enjoys a little shock to the collective system, and after offering such a big-boned orchestral tone, he tinkered with it in a nod to periodicity. The kettledrums were smaller than those usually employed today, and were played with the hardest of sticks. This fostered the illusion of an early-19thcentury orchestra, perhaps more apropos of Beethoven but interesting in Mozart nonetheless. Also, the conductor engineered a very contemporary-sounding fade-out at the conclusion of the Adagio: Allegro, more Hollywood than Vienna. Its inspiration may have been the ultimate farewell in this sym phony, a “fade to black” that was rather revolutionary in Wolfgang’s time.

Although this first performance was fine, the heavy-footed traversal of the Concerto for Two Pianos, K. 365, reminded me more of circus bears in ruffled collars than delicate pairings of dancers from the Maria Theresa period. Mr. Barenboim has the impolite habit of placing his own piano smack dab in the middle of the stage and facing rearward. Although there have been some evenings when I longed to see the back of him, this was not one of them. As for Mr. Lupu, he was positioned to face the maestro and rendered invisible somewhere in the bowels of the woodwind section. There was, as they say in Brooklyn, a lot of fat-fingering going on in this piece.

After intermission, the group presented a high-energy, if ultimately unremarkable, Symphony No. 41. Showcasing a faster than normal tempo, Mr. Barenboim delivered an exaggerated downbeat to begin the piece, and his charges responded reasonably well. I’m sure the Staatskapelle players are tired of hearing this, but they are not the Berlin Philharmonic; still, there was much solid playing this evening. Of special note were the tightness of the string sections (which were reduced in numbers for this program) and the lyrical grace of the principal clarinet.

Overall, this was pleasant music pleasantly played, but lacked the grandiloquence of this perhaps greatest of all symphonies. The god in question seemed more of a minor deity – Mercury perhaps, but not Jupiter.

A week ago, Mr. Barenboim collapsed in Berlin and was hospitalized with balance problems. It is comforting to report that on Saturday he looked none the worse for wear.

***

The first thing I noticed about violinist Joan Kwuon, who gave a recital Friday evening at the Metropolitan Museum, was that she has a healthy disregard for the accepted method of performing Mozart in modern circles. Ms. Kwuon has no compunction about using a big, bright tone with considerable vibrato. She sounds entirely different from the standard scholarly reconstruction of the original violinist – Mozart himself – who presented these pieces to the world as a young man.

The two short and showy works she played were the Adagio in E major, K. 261, and the Rondo in C,K.373.Presenting them together was very effective; since one compliments the other in the manner of the sonatas of the day, written before the sonata form was identified and standardized, this made them seem like two movements of the same composition. With her unabashed contemporary sound, Ms. Kwuon emphasized the playfulness of the latter piece.

Next Ms. Kwuon essayed George Enesco’s Sonata No. 3, subtitled “Dans le caractere populaire roumain. “This is the greatest work of a towering figure in violinistic history – and one of the greatest of all 20th-century compositions. Romanian blood flows within me, so I might not be totally objective, but this essay on the employment of folk elements into the strictest classical forms is a masterpiece.

More relevant for Ms. Kwuon is the sheer artistry necessary to pull it off. It’s Olympic season again, and so degrees of difficulty are in the news. This sonata is definitely a 10.

Ms. Kwuon and her accompanist, Christopher Oldfather, caught the spirit of the Moderato malinconico, with its medieval evocation of the wolves just beyond our ken perpetually haunting our every move. In the second movement, Andante sostenuto e misterioso, this versatile violinist was particularly expressive in the many pizzicato and unnaturally high-E string effects; only an occasional wrong note or finger slip tarnished the mood. But the Allegro con brio ending, which needs to be delivered with reckless abandon, proved just a tad beyond their reach. Ms. Kwuon had to take a gingerly approach to keep from veering off of the road entirely.

Even more demanding is the fuga section of the mighty Sonata No. 3 in C for solo violin by Johann Sebastian Bach. Here the performer has no place to hide, no piano to spell her, however briefly. Bach amazingly creates a section that sounds like several instruments locked in one of his contrapuntal labyrinths, but, of course, it is written for only one violin. Although Ms. Kwuon played the remaining movements, especially the Allegro assai, with a good deal of brio and technical surety, she could not handle this majestic fugue. She even stopped occasionally, however briefly, and had a deuce of a time sustaining the harmonics necessary to create that multiple-player illusion.

Ms. Kwuon ended her program with a piece, “Tango Song and Dance,” written by Andre Previn for his wife, Anne-Sophie Mutter.