Even in their usual configuration as a street corner quintet, Sweet Honey in the Rock can make a big, joyful noise. Last night at the UDC Auditorium, their numbers swelled to 15--the size of a choral ensemble or more accurately a gospel choir--and the waves of a cappella harmonies came from three times as many directions with three times as much power.

It was like the difference between a jazz combo and a big band. Standing in brilliantly colored gowns along a long crescent line, they improvised on Langston Hughes' poem, "A Dream Deferred," with gospel hums, blues shouts, rumbling moans and piercing falsetto cries, all held together by a swaying beat. The group's 10th anniversary was as emotional for the singers as for the longtime home-town fans in the sold-out hall.

The group's unchanging core through 10 years has been Bernice Reagon, who supplied the chilling political narrative to "Fannie Lou Hamer" and the tour de force rhythm and blues solo to "Hey, Man." For the finale, 21 workshop participants joined the 15 members on the "Azanian Freedom Song."

Sweet Honey in the Rock's 10th anniversary concert will be repeated twice tonight.