Once the community along Washington's Anacostia River was white and working class, populated by refugees of southern poverty and soldiers-turned-government workers. Today that same section of Southeast Washington is virtually all black, and things have changed as the whites moved to the suburbs.

But on weekend nights, the old residents of the area return like ghosts to El Brookman's, an old brick bar which has stood for 30 years as a community playroom. There the old-timers mix with local blacks and a few, drifting members of Washington's young, hip community to listen over beers to a strange combination of country music and avant-garde comedy.

Aiding improvisational comedy to the Brookman's established country act is the idea of Paul Brookman, the 22-year-old son of the bar's founder, one-time Golden Gloves champion John "El" Brookman. Like the Improv in New York or the Comedy Store in Los Angeles, Brookman hopes the new comics will attract a young, more affluent crowd to the old bar.

"It's a conceptual thing we're trying to do, to give a showcase for local talent," Brookman, dressed in a blue Marx Brothers T-shirt, said. "Young people don't wnat to come to Washington anymore unless it's that Georgetown trip - they'd rather get pick-ups at the discos in the 'burgs.' We're try)ng to provide an alternative."

If he's serious about making the country and comedy combination work, Brookman has a long, rough road ahead. Perhaps their biggest problem, Brookman says, is their location.

"Nobody will even come out here to look at us," Brookman complaints. "That's because the media thinks all the entertainment is in the Northwest or Georgetown because that's where the right people go. They won't even look at us because we're in an all-black area like Anacostia."

"This really isn't that bad a part of own," insists Eleanor Brookman, who has been running things around the bar for the last 30 years. "You know, there's a lot of good going on here - as much as Georgetown. There are everyway people here and they're as happy as people in Northwest."

This is no hangout for the fashionable crowd, that's for sure. Mostly, the people here are dressed in T-shirts, jeans and old dresses and pull up to Brookman's in old cars usually parked in suburban Maryland driveways. Beers are bought by everybody for everybody at a furious pace, and the smell of ale, the sound of country music and the hanging cigarette smoke give the whole place the feel of a late-1940s hangout.

Coming out between the country band's acts, the young comedians are basically lambs for the slaughter. Their jokes, either political or about topics dear to the youth culture, usually land with an unceremonious thud - even among the few young people sitting in the back.

When Magnum Force, a two-man "avant-garde" comedy act, tramped out and went through a series of rambling, usually incomprehensible skits, the older, T-shirted men at the bar hooted and hollered with a vengeance. "Man, that's a tough audience," said a sweating Jay Earmshaw, 24, of Magnum Force after coming off the stage.

Joe Norris, the 23-year-old coordinator of Brookman's comedy acts, most of which respond to newspaper ads, looked embarrassed and went outside for a few gulps of humid air. "Damn, we told told them it was too avant-garde," Norris complained amidst the neon haze of Pennysylvania Avenue. "We told them to bring it down to the mediocre level of our audience here but I guess it didn't work."

Some of the regular Brookman customers, like 50-year-old Jim Bradley, feel the comics are an intrusion into the close-knit, well-worn world at the bar. "I come here for country music not comedy," complained Bradley, a native a Alabama and now a Washington postman. "This is what I'd call a redneck bar and all this fancy comedy doesn't make it here."

It's no easier for young, talented comedians like 28-year-old Louis Black whose current jokes about the neurton bomb - "It keeps the buildings standing but who for?" - got only heckling from a regular named "Smokey" who screams, "That's not funny - I wanna a war" throughout the routine.

Stuck on the stage, Black maintained his composure, and saved the show with a few, well-timed jokes about drugged-up football players. A small claque of young people applauded in the back. "Thank God for you folks," Black said as he left the stage.

Later on, after a few beers, the graduate of the Yale Drama School sat running his fingers through his black, curly hair and dreaming about better days in the future in either Los Angeles or New York. "I'm only here because I'm totally unemployed and I know the turf here," the native Washingtonian droned. "This is only a place to train. You don't get the audience, you don't get the money, you don't get the critics, you don't get anything."

When the comedians were through, things ligthened up. "Tiny" Crutchfield, a huge, potbellied man with long, gray and white whiskers, played his guitar for thoroughly ecstatic, dancing, beer-drinking couples who hung onto each other in the night. By the time it was almost 2 in the morning, smiles were cracking even unto the faces of the comedians.

Louis Black and friend were up dancing in a circle of people which included the hecklers of just a few hours before. Paul Brookman watched over the social hodgepodge and offered his only justification for the spotty performances during the evening.

"All right, I admit the comedy's not too good sometimes," he said with a little apologetic smile. "But some poeple listened, some people laughed and everybody had a good time - and, really, that's all that matters."