In Paul Hindemith's Sonata for Viola and Piano (Op. 25, No. 4), the effect of Carpenter's lucid, supple, minutely purposeful playing was curious. Never before have I heard the piece played without a considerable and constant sense of physical effort. I had come to think of this as almost part of the score, so it was something of a shock to hear the piece with the toil stripped off, as it were. What the composer would have made of this performance, I have no idea. Hindemith's own viola-playing, well-documented on disc, had roughly the aural allure of a band saw cutting tin. No one can go through his music of the 1920s without understanding how the physicality of performance was at least part of the point of the music.

But here was a flawless and disarmingly easeful performance of a piece that I'd always thought was designed specifically to be heavy weather — and, mirabile dictu, the piece turns out to be even better music when it doesn't sound like hard work. Take away the husk of effortfulness, and the slender shape that remains is uncommonly elegant of construction and of line alike.

Carpenter didn't work such a transformation on the Brahms, but then he didn't have to. His playing seemed to me perfectly judged, neither overheated nor imitation-clarinet cool. And he left a fair number of passages down an octave where Brahms put them, rather than playing them in clarinet register, as some hot-shot violists prefer.

After the Hindemith came a pair of pieces that must have affected some concertgoers, accustomed to modern ideas of recital design, like a thwack in the posterior. It wasn't really all that long ago — a generation or two, tops — when the show-offy stuff now classed as "encore material" was on the printed program rather than after it. That was the environment in which William Primrose made a go of it as a viola recitalist. Because he had received a first-class violinistic education before switching instruments, he did his best to add material of that kind to the violist's meager stock.

Carpenter played Efrem Zimbalist's Sarasateana (potted Pablo de Sarasate, slightly thickened in the piano department and adapted for viola for Primrose), followed by Primrose's own transcription of Paganini's La Campanella. This is music you'd be a fool to program as a violinist if there were any chance you'd look as though you were exerting yourself. On Carpenter's chosen instrument, it is several times more difficult. Did he even seem to be trying hard? Nah. He looked like a guy who thought it would be fun to end the evening by showing his teacher exactly what he could do under pressure.

Carpenter's teacher is Roberto Diaz, the former principal viola of the Philadelphia Orchestra and now president of the Curtis Institute (as was Zimbalist). A couple of years ago, Diaz recorded a disc of arrangements by or for Primrose, including La Campanella and also Sarasateana. (One Robert Koenig is the pianist on the recording — coincidence?) "Diaz playing Primrosiana," I thought when the disc came out, "made it sound too easy." Carpenter, for better or for worse, makes it sound much easier than his teacher does.

I wished Carpenter's encore had been in another vein, because he certainly had the means to play any short piece he wished. He chose the Dinicu-Heifetz Hora staccato, in what I think were the original violin key and octave. It certainly demonstrated that Carpenter has a mean, tight down-bow staccato, but we had been amply informed of the up-bow staccato a couple of pieces back. Never mind. Anyone who didn't enjoy that swaggering performance is fun-deprived. We violists — and the audience was full of us — thought it a hoot.