Black History Month is half over, but the special events observing it don't show any signs of winding down. This is an especially lively weekend, starting with free natural history films (things like "Zulu Country Dance" and "Africa Calls: Its Drums and Dances") Friday at noon in the Museum of Natural History's Baird Auditorium. Saturday at 3 you can see more films, at the Museum of African Art, 318 A St. NE (a $1 contribution's required for non-members).

Then wander over to the People's Congregational United Church of Christ at 4704 13th St. NW: They're having a free Caribbean Festival from noon to 5.

Sunday you can bone up on African culture and history. At 3 there's a lecture on African sources in modern art at the Museum of African Art. Later, from 5 to 9, the National Park Service is sponsoring candlelight tours of "Cedar Hill," 14th and W Streets SE, home of abolitionist Frederick Douglass (above). Information and reservations: 889-1736.

Tuesday through Thursday afternoons, there's a free Black History Festival a the Fort Dupont Activity Center (off Minnesota Avenue at Randle Cirlcle), with exhibits, films and music from 1 to 2:30 (426-7723). And Thursday night at 8, poet-singer-actress-songwriter-director Novella Nelson will perform at Baird Auditorium Sounds like a bargain for $6. Details: 381-5157.