The Contemporary Music Forum once again showed itself to be one of the strongest and most exciting ensembles around.Last night at the Corcoran Gallery not all of the music merited the fine playing, but the musicianship and versatility was often thrilling enough.

The playing was in fact the only memorable thing about thw world premiere of Brian Bennett's Quartet for Strings. There were distant echoes of Ives and Skalkottas, and even some lovely textures in the finale. But it remained by and large a crafty exercise rather than a creative synthesis, with short phrases that were never succinct and a curious dynamic and rhythmic sameness that rambled out of the realm of interest. There was impeccable commitment from cellist Mary Jean Kraft, violinists Helmut Braunlich and David Brewster and violist Nicholas Marlowe.

To Braunlich go the top honors for his intense rendition of Bartok's Sonata for Violin. Like ybennett's Quartet, the Sonata is at times more concerned with form than with content, but its intricacies are in themselves fascinating and, with Braunlich's cool assurance, quite irresistible.

The concert, which closed with Ruth Crawford Seeger's 1931 Quartet for Strings, will be broadcast on WETA on March 26.