"It's Washington's best-kept cultural secret," says Gail MacColl about the D.C. Community Orchestra. When it started up "one year before the National Symphony, it was the only orchestra in Washington," continues MacColl, violinist in the orchestra and president of the association that supports the group in conjunction with the D.C. Department of Recreation.

The orchestra will celebrate its 50th anniversary at 3 p.m. today with an all-Mozart concert at Takoma Theatre, Fourth and Butternut streets NW. The deputy mayor for economic development in the District, Curtis McClinton Jr., will be the guest vocalist.

"We bring live cultural music to people who don't have access to it regularly," MacColl says, referring to concerts for the Washington Center for the Aging and the Roosevelt Home for Aging Citizens. "We cater to the community -- families with kids who find it hard to get out. Our audience is not the Kennedy Center subscriber." The group has also undergone name changes -- it was orginally the Washington Civic Symphony, then the Baroque Arts Chamber Orchestra. It assumed its current name in 1976.

Some members of this volunteer orchestra have been playing with the group for more than 30 years. Violinist Betty Bushell, 67, who joined the orchestra 38 years ago, says, "When I first started it was a huge orchestra -- 70-some people. Sometimes you had to sit behind the curtain." Over its half-century life with conductors coming and going, members have come and gone, too. Membership swelled to 120 in the late 1930s and shrank to five in the late '70s.

"It became difficult to get players. There were a number of other orchestras coming into the scene -- Arlington, Montgomery, Georgetown. With a lot of groups, our supply was depleted," says Bushell.

A diverse collection of amateur performers, the group, MacColl says, includes, "some members like myself who started playing when we were children and kept up. Some picked up playing later. One cellist started when she was 64." And a newcomer to the 36-member orchestra is a Woodrow Wilson High School senior, Michael Middleton. The principal percussionist for the orchestra, Middleton also plays in a rock 'n' roll band.