When the Colorado String Quartet played Mozart yesterday at the National Institutes of Health, it left the impression it shouldn't be playing anything but Mozart, so thoroughly did its members understand his idiom. When they played Berg, they left the impression that it is to Berg they should devote themselves, so clearly did they understand his composition. By the time they played a final work by Beethoven, it was obvious they should perform any piece their protean talents inspire them to study: The result will be only the best of performances.

The Colorado Quartet's versatility manifested itself when, after a lyrical and technically clean but restrained rendition of Mozart's "Quartet in A Major," K. 464, the players launched into the tonal, timbral and rhythmic jungle of Berg's "Quartet," Op. 3. Beethoven's "Quartet No. 10 in E flat," Op. 74, enjoyed its due as well -- in a technically careful but spirited performance that made good use of the strong ensemble that characterized all the group's work.

The quartet's attention to detail, polished technique, respect for stylistic idiom, and breadth of repertoire resulted in a performance easy to enjoy but difficult to match in musical integrity and talent.