The Guarneri String Quartet (playing as guest artists of the Chamber Music Society of Lincoln Center) waited until after intermission before confronting any serious musical or technical challenges Saturday night at the Kennedy Center.

When those challengers finally came, however, in the youthful, dramatic Brahms Quintet in F minor for piano and strings, the ensemble responded superbly. Pianist Richard Goode seemed to set the tone of the interpretation, wringing the stormy rhetoric of the score for all it was worth and sometimes perhaps a bit more. The quartet matched his intense statements phrase for phrase, with results that came close to overstatement but worked superbly. As always with this quartet, the playing was nearly flawless, and the trickly balance of piano and strings was masterfully handled.

The effect of near-overstatement may have arisen partly from the sharp contrast with the Mozart flute quartet and the string quartet dating from Schubert's teens which opened the program - easygoing, tuncful music written for informal performance by amateurs. A group like the Guarneri (and flutist Paula Robinson, who played beautifully in the Mozart) could sight-read this music with few problems. And that doesn't mean that these two pieces were anything less than a sheer delight in their unproblematic way.