Concord String Quartet, which performed at last night's Kindler Foundation Concert at the Library of Congress, may be justly famous for premiering new works, but its Dvorak is nothing to be sneezed at either. The quartet concluded an unusually interesting program with a profound and intense reading of the G Major Quartet, Op. 106, that projected vastness while at the same time preserving a clear sense of structure and orientation.

One of the things this ensemble does best is signal its musical intentions, not self-consciously, but with a commonly felt rhythmic direction and integrity. This is what gave the Dvorak such clean outlines and what made its performance of "Quatuor III" by Betsy Jolas so lucid. The Concord premiered this piece back in 1974 when it was commissioned by the Kindler Foundation, and its plays it with authority. A set of nine brief e'tudes on aspects of string technique, this music focuses on textures and sonorities, what linear writing there is being relegated to the two aleatoric (semi-improvised) movements. It is delicate, witty and subtle music and, most tellingly, it is interesting.

The program opened with a rather remote performance of Haydn's B Minor Quartet, Op. 33 No. 1.