There's something to be said for youth. But what is it? The Dryden Quartet was tremendous fun Monday night in their Philadelphia Chamber Music Society debut, all verve and brightness. Those of us who remember running into violinist Nick Kendall trash-can drumming on a Center City street corner when he was a Curtis student see in his string-quartet playing a joy undimmed by time. But as violist Daniel Foster told the audience at the American Philosophical Society, this is a part-time ensemble. Three of its members have full-time jobs with major orchestras, and Kendall is one-third of Time for Three. In Haydn and Schubert, high spirits could carry them only so far. Still not in place for the Dryden is real personality and the razor precision that comes with life together on the road.

Their potential is limitless, which is what makes the future worth pondering. They chose one piece extremely well: Ginastera's exhilarating String Quartet No. 1 of 1948, which required all the physicality of Bartok and an ability to outlast a moto perpetuo or two of epic scale. The Dryden conquered - technically and stylistically. Haydn, less so. This repertoire is exposed, and the D Major, Opus 50, No. 6 quartet, "Frog," is particularly bare. It was striking to hear the Dryden just a few days after pianist Christian Zacharias, he of the philosophy that the written note sits there begging to be violated. The Dryden treats the score as sacred, and the resulting Haydn was a little shy on imagination.

Glimmers of what is possible arrived in Schubert's String Quartet in A Minor, D. 804, "Rosamunde," where Nurit Bar-Josef, concertmaster of the National Symphony Orchestra, felt emboldened by the time shift in periods. Expressively, she grew phrases. Emotion entered the picture. You hoped cellist Yumi Kendall - acting associate principal of the Philadelphia Orchestra - would take hold of the stirrings of the Romantic period with a little more force. Sturdy if quiet, Foster is principal violist of the National. While there was nothing wrong with any of this, the players seemed to need a fifth element to fully ignite, as if they were waiting, as they are accustomed, for the conductor to light the way into realms of meaning behind the printed page.