Judging by the quality of the music-making Saturday night at the Kennedy Center, no one in the audience would have suspected that violinist James Buswell was substituting for an ailing Shlomo Mintz. Mintz, who was to appear with the Chamber Music Society of Lincoln Center, had been scheduled to play in every work. Buswell took over the program intact, frequently spurring on his fellow Society members with the subtle radiance of his playing.

It was -- given the Society's recent propensity for schizophrenic shuffling of players and pieces -- an exceptionally coherent evening, focused on uniformly ingratiating, if not profound, offerings. The easy grace of Mozart's E-Major Trio, K. 542, was realized with a transparent brightness by Buswell, pianist Andre-Michael Schub and cellist Leslie Parnas. The modest dimensions of Schumann's first violin and piano sonata fared equally well under gentle, lyrical treatment from Buswell and Schub.

The cozy atmosphere received a welcome jolt with Bela Bartok's fiercely original "Contrasts" for violin, clarinet and piano. Ably accompanied by Schub, clarinetist Gervase de Peyer joined Buswell in a virtuoso exploration of the work's dramatic extremes. Mendelssohn's second Quintet for Strings, interpreted by a superbly blended and unified ensemble, restored a final note of tranquility.