A group calling itself the Fitzwilliam String Quartet might be expected to specialize in the music of Dowland and Purcell, or perhaps Britten and Vaughan-Williams. Instead the ensemble, which began as an undergraduate pastime at Cambridge, has made its name performing and recording the quartets of Shostakovich. The quartet played his F minor quartet Op. 122 at The Barns of Wolftrap last night, and it was clear right off the bat why the Russians rather than the English are its composers of choice.

This is a robust ensemble, one not given to fussy details or delicate mannerisms. The quartet's playing is earnest and forthright and allows no frivolity and precious little levity.

The opening Tchaikovsky B flat major quartet displayed the group's strengths admirably. The two misterioso movements that flanked the rather self-conscious allegro had a somber and sonorous intensity that was vintage Tchaikovsky.

The fanciful Shostakovich was marvelous. The musicians captured the spirit of inventive variety, exploding with a burst of energy, reveling in opportunities for solo declamation and ending with a dark elegy. These are musicians who have been able to retain their individuality as soloists while managing unusual balance and accommodation when playing together.

The concert ended with the Delius Quartet, overlong and unrelenting in its glorification of the ninth chord, and a lucid and vigorous performance of Beethoven's "Grosse Fuge."