Leon Kirchner, whose Trio No. 2 for Violin, Cello, and Piano was performed on Sunday by the KLR trio at Carnegie Hall, had his career as a composer at least partially derailed by Leonard Bernstein. Just after Mr. Kirchner had convinced Dmitri Mitropoulos to program his Piano Concerto with the New York Philharmonic in the 1950s, Bernstein took over the orchestra and banned serialism altogether. Mr. Kirchner became an academic, following Arnold Schoenberg down a rabbit hole of music history.

By the time the members of KLR — Joseph Kalichstein, Jaime Laredo, and Sharon Robinson — approached the former Young Turk in the early 1990s, his style and harmonic language had radically changed. His resultant trio sounds more like a piece from the epigones that succeeded the finde-siècle Viennese, and could have been penned by a Franz Schmidt or Alexander Zemlinsky. KLR gave it a solid performance, but the work itself is quickly forgettable. Even though some isolated moments could pass for beautiful, the work engenders the nagging suspicion that the Kirchner who wrote his first piano trio 40 years earlier would have thought the later work hopelessly saccharine. From the 1960s, his work retrogressed into kitsch, and this piece could have easily been from a movie score, or even background for a television spot.

Franz Schubert avoided all of this middle period versus late period nonsense by dying at 31. Still, he composed roughly a thousand works, from the dramatic songs, such as the Erlkoenig, which he wrote at 17, to the posthumously published piano sonatas. Virtually all of them are superb. The KLR trio members, plus two (Pinchas Zukerman, viola, and the principal bassist of the Philadelphia Orchestra, Harold Robinson), presented the most beloved of all, the “Trout” Quintet.

Playing chamber music at Carnegie Hall is tricky. The acoustics are geared toward a larger ensemble and small groups must not attempt to adjust their volume to the point of distortion. This veteran group did not overcompensate, but produced a rather thin finished product. Had the performance been a fine one, nobody would have quibbled about its decibel level. Unfortunately, it was not.

The “Trout” is a familiar work, and each of these players had been playing it regularly since summer camp. They sounded like it. What should be a terrifically exciting journey instead simply bored its own performers, who never approached its emotional or rhythmic center. There were isolated phenomena to praise — particularly the coordinated precision of the two Robinsons. But overall the playing was mechanical, stiff, pedantic. It seemed particularly profligate to gather five of the world’s most competent chamber players, put them in the best concert hall on the planet, and then produce such an exercise by rote. The “Trout” and the audience, who braved flooded subways and torrents of rain to get there, deserved better.

And they received better in a sensitive reading of the E Flat Major Piano Quartet of Mozart. Wolfgang’s project to publish three of these pieces for use in the home was such a commercial failure that he never even composed the third of the set, but the two extant are both charming and profound. This rendition provided unabashed Romanticism, with Mr. Laredo caressing his phrases with generous vibrato — a studied contrast to Mr. Zukerman’s more straightforward declamations. Ms. Robinson deployed that rich, burnished cello tone while Mr. Kalichstein put on a clinic on the subject of the lightness of keyboard touch.

Before us was emotional Mozart, with phrases endowed with eloquence and warmth. It was enough to give a period instrument devotee the vapors. This was politically incorrect music making, and I loved it.