The Fortas Chamber Music Series continued Saturday night at the Kennedy Center's Terrace Theater with a performance by the Ridge String Quartet, a very young group that has already acquired a good reputation in only a few touring seasons.

The Ridge seems to have the basics for success -- its members are technically proficient and they respond fairly well to one another. Yet their playing is often marked by a narrow vision of interpretation that does not permit the quartet literature to stand on its own.

For example, Haydn's Quartet No. 5 in G, Opus 17, in which a wide variety of texture and line is an important consideration, appeared flat and one-dimensional.

The beautiful "conversation" sequence of the slow movement failed to go anywhere, and the brilliant writing for first violin was cast in a sugary, overly sentimental mold.

Barto'k's exacting, symmetrical Quartet No. 4 showed a better formal insight, and the many coloristic effects came off well.

Still, the rhythmic and emotional tensions were too lax. Joined by pianist Stephanie Brown, the Ridge was more comfortable in Dvorak's Quintet in A.

The harmonic colors and fast mood swings were executed with strength and greater stylistic refinement.