For violinist Joseph Silverstein it must be like a return to his days with the Boston Symphony Chamber Players, these Nova Chamber Music Series benefit concerts he has played nearly every year since coming to Utah.

Thus this year's edition, Monday at the Museum of Fine Arts, again found him holding down first fiddle in an ensemble of mostly Utah Symphony musicians, this time in - surprise, surprise - an evening of Mozart.Not Mozart we hear all that often, however, in this case being the Divertimento No. 17 for Horns and Strings, K. 334, and the E flat major Viola Quintet, K. 614.

Turned out on spec, as it were, for the Prussian monarch Friedrich Wilhelm II - himself an amateur cellist - the K. 614 Quintet is the last of six such works we have from the composer's pen, indeed his last piece of chamber music of any kind. Yet the music itself recalls Haydn as much as Mozart, in yet another tribute to the contemporary Mozart himself most admired. (The feeling was mutual.)

Here, with Silverstein and Nova Series music director Barbara Scowcroft on violins, Utah Symphony concertmaster Ralph Matson and Cathryn Manning on violas and Ellen Bridger on cello, it came in for a gently contoured reading, a bit relaxed in the opening "hunting" movement but remarkably lithe and quick in the mercurial finale.

Throughout balances were subtle (even if they did take a while to settle in), with Silverstein's fiddle glistening amid the rest, followed by Matson's surprisingly full-toned viola solos. That was especially true of the Andante, with its supremely Haydnesque main theme, despite an occasional touch of sourness. Nor was there any mistaking Silverstein's sound over the bagpipe-trio of the minuet, coming between the modified lift of the outer sections.

If anything his playing was even more to the fore in the K. 334 Divertimento that followed, given its concertante quality and especially prominent first-violin part.

Here, in addition to Scowcroft - who made a fine thing of her occasional solos - Matson and Bridger, his partners were horns William Barnewitz and Sue Hudson and double bass James Allyn. The result was a spirited rendition, befitting the music's more open-air quality, yet generally well-controlled, especially vis-a-vis the horns. Which, needless to say, are not easily balanced against five strings.

Once again, though, it was Silverstein's playing that stood out, whether singing semisweetly through the rest in the opening Allegro or via his beautifully shaded solo work in the second-movement Theme and Variations. Likewise the silvery elegance of his sound in the familiar first minuet, which here tripped along just a bit heavily, and the poignancy he brought to the Adagio, conveying more depth than is common in a divertimento.

That effectively counterbalanced the comparative vigor of the second minuet, here with a sonorous finish, itself preparing the way for the graceful lilt of the finale, which gained in force as it went along.

"This performance is coming to you courtesy of Xerox," Silverstein was heard to crack as the players wrestled with the music before launching into the concluding Rondo. But as Scowcroft made clear in her intermission remarks, it really came courtesy of all those who donated their services, not least the speaker himself.

Monday's concert will be broadcast Monday, April 29, at 9 a.m. on KUER-FM, in case you missed it. Or in case you'd just like to hear it again.