Brentano Quartet and Marina Piccinini in Kernis premiere at the Kimmel

Every listener has a work that makes him wince, and mine is that reliable musical patron saint of tasks dull and dutiful, Mozart's Flute Quartet in C Major, K. 285b. The lack of tension and harmonic interest in the first movement opens up to a bit more nourishment in the second, but the best possible thing that could happen to it came Wednesday night: the intriguing sound of its lead voice in flutist Marina Piccinini.

The main event perhaps at the Philadelphia Chamber Music Society concert at the Perelman was the Philadelphia premiere of Aaron Jay Kernis' Air for Flute and String Quartet, lovingly realized by Piccinini and the always-warm Brentano String Quartet. The work is from 1996, two years before the Bensalem-born composer won the Pulitzer in music for his second string quartet, and more amiable writing might not exist.

Flute is dominant (it even gets a cadenza), but the overwhelming asset is mood, and the strings lay it on like silk. Agitation arrives toward the middle, but for the most part Kernis' Air is quietly expectant in a gentle world. Vaguely touched in Americana, its lyrical tones reassure the way Gerald Finzi's Eclogue for Piano and Strings Op. 10 does — which is to say, as a welcome pool of tranquillity in unsettled times.

Piccinini in both Mozart and Kernis came across as a sensitive player with a deep sound that grows and stretches to suit the specific emotional intent of the moment.

Two works for string quartet alone occupied the Brentano the rest of the program, which was dedicated to Michael Tree, the Guarneri Quartet violist who died Friday. The Brentano's marvelous qualities shone through both the Mozart String Quartet in C Major, K. 465 and Beethoven String Quartet in C Minor, Opus 18, No. 4.

There is no single star in this group, though violinist Mark Steinberg has a lithe charisma that is nicely understated. What's impressive is how they nestle up inside each other's sound. The Mozart had them comfortable and confident, putting more emphasis on beauty than polish per se.

They caught Beethoven's shifting spirit in the Opus 18, No. 4, from the coiled anger of the opening to the jumpy third movement. You might have wished for more saturated emotions at times. But the end of the second movement showed what subtle messaging comes when like minds have been quartetting as long as these have (since 1992).

In the last 16 bars or so, they changed their character slightly. It was a charming draining away of tension that made all concerns evaporate.