Bright Morning Star, six socially and politically committed folk musicians, came together "because we kept meeting each other at rallies" up and down the East Coast, says fiddler Ken Giles, the only Washingtonian in the group. That was in 1980, and since then Bright Morning Star has become a lively and engaging fixture in the peace and antinuclear movement. The group will perform at 7:30 tonight at Temple Sinai on Military Road; it's part of "Rainbow Sign Celebration," a day-long teach-in on nuclear disarmament.

The group, which comes together for major tours in the spring, summer and fall, draws its other members from New England: Cheryl Fox and Marcia Taylor are from Boston, Court Dorsey from Norwich, Conn., and Charlie King and George Fulginetti-Shakar from Amherst. They appear at rallies and public events for safe energy and peace, "and we also do concerts, which are more supportive of local groups because they can be used as an organizing tool and for fund-raising," says Giles, who works for the Consumer Products Safety Commission.

About 50 percent of the music originates within the group, which also draws on the rich folk-music tradition. "We've deliberately been singing a couple of the Weavers' songs because the more we've educated ourselves about modern folk music, we see the debt we owe them and the Almanac Singers. We address a lot of issues and feel a real positive response, a wonderful coming together," says Giles. For information on the concert and teach-in, call 686-9479.