No longer in need of the nurturing of its early days, the Contemporary Music Forum has become well enough established to be judged by the usual concert standards. On that basis, the chamber ensemble's program last night at the Corcoran Gallery would not rank high; it failed to match some of the Forum's own previous high points.

Although it was certainly commendable that the first half was devoted to composers from the area, some questions could be raised about both music and performance. By far the best on both counts was Robert Parris' "Duo for Violin and Flute," an intimate exploration into the similar ranges and contrasting colors of the two instruments, given a delicate interpretation by flutist Toshiko Kohno and violinist Helmut Braunlich. Less satisfying were two works for solo piano, Emerson Meyers' "Rhapsodie Fantastique" -- almost all craft and little communication -- and Sotireos Vlahopoulos' pleasant but rather ordinary "Suite: Iberian Sketches." Both received lucid, well-articulated, yet curiously neutral, treatment from pianist Barbro Dahlman, who maintained an emotional distance from the music.

In the second half the group turned to George Crumb's familiar "Night of the Four Moons," a piece that demands the most careful balancing of sonorities. The Forum's performance showed signs of carelessness about important details -- for example, whispers that were drowned out, a different-sounding farewell stroke on the small brass cymbal from each of the musicians -- that robbed the work of much of its mystery.