This is supposed to be the summer of the great Bicentennial letdown. Quiet dignity, reserve, even boredom are the fashionable words for July 4, 1977.

Maybe that's the way it looked in Washington, but out in Dale City, 30 miles away amidst the green forests of Northern Virginia, they're saying it was the best Fourth yet. This year they all came marching down Dale City Boulevard - the fife and drum team in colonial knickers, the National Guard, the Marines flying the colors, clowns, even a float with a matronly housewife dressed like Athena holding up a large stars and stripes.

Parade Judge Tom Brenzovich waited nervously as the sirens of the oncoming Dale City Volunteer Fire Department trucks heralded the approaching throng. "It's an old tradition, this parade, and so much of our traditions are being lost - good ole Fourth of July, apple pie and all that," the 33-year-old HUD computer expert complained. "People are too busy nowadays worrying about mortgage payments to worry about things like this."

It wasn't easy finding a good parade in rural districts of Northern Virginia this year. Many little towns have, year by year, canceled their festive marches citing costs, other diversions and general lack of interest.

"The fire departments and the sheridd just want to keep the equipment around on the Fourth these days," explained Fauquier County Sheriff's Deputy Frank Covert. "It's getting too expensive to have parades. There used to be more but now they have sort of died out."

Brenzovich watched the National Guard parade a recoilless rifle and an armored personnel carrier past the housing tracts of this town of 50,000 on the edge of suburbia.People applauded. "We get a kick out of this stuff here," he said, smiling and smoothing back his hair. "The other communities don't do it because Dale City's got the best."

In the 90-plus degree heat, master of ceremonies Bill White wiped his forehead and described the affair to onlookers. A onetime country singer with "Cousin Ray and His Country Cousins," White announces with a Southern monotone which sounds very much like President Carter.

White, or "The Virginia Troubadour" as he likes to be called, burst with pride as four troops of tiny, blue-clad Cub Scouts marched with little steps down Dale Boulevard. "It's the beginning of manhood, folks," he commented to the applauding crowd. "You got any kids, now, you get them into that Cub pack and they'll turn out alright."

Then came the car bearing Debby Apperson, tanned in a sleeveless summer dress, waving to the crowds. A little sign on the car read, "Miss Prince William County." The Virginia Troubadour found it hard to restrain himself.

"Ooo-wee, she's a fine looking woman," the potbellied White crooned. "We've fallen in love with her already."

Later on, the shy, dark-haired Apperson stook with a bouquet of flowers, discussing her ambition to become Miss Virginia later this month and then on to Miss America and, maybe, a career as a model in faraway Los Angeles.

"I like to go to parades, I love crowds and people," she giggled in the sun. "I just love crowds and attention. I'm a ham. I guess that's how you could put it."

The parade drew near a close with the approach of several overweight soldiers from the Veterans of Foreign Wars, sternly marching with flags held high. Patriotism may be dying around the country, said Lou Mitchell, onetime Dale City V.F.W. commander, but not here, not on the Fourth of July.

"A lot of people are just not getting it together today. Businessmen don't want to part with their money, people are uninterested because we've let those deserters back," the bemedaled veteran said. "Darn, its hard to bet a person even to wave a flag, most of the time you got to beg him."

Despite the festivities in Dale City, the Fourth isn't what it once was in the rural reaches. It used to be a bigger deal one time in sleepy farming towns like Catlett (population 500), 40 miles from Washington.

The Fourth of July festivities were always something special in Catlett. Starting back in 1915 there were always marching bands, all-night music shows and political speeches.

"It used to be a real all-day and evening affair," recalled Roy Wilson, 72, chairman of the Catlett Ruritan Club Patriotism Committee. "My God, it was the biggest thing happening in this area. The Fourth of July in Catlett - it was the event of the year."

Today, thanks to television, looser community ties, all this over the years, "has sort of petered out," Wilson said sadly. But every Fourth of July, for a few hours in the early evening, people still come to the fairgrounds behind the white Catlett Fire Hall to enjoy the little rides and fill up on homemade cakes, hot dogs, sticky cotton candy and buttered popcorn.

Wilson moved some benches, preparing for the annual Fourth of July Bingo Game, which he has run every year since 1929. "I think this should be perpetuated even though some people make fun of it," Wilson said. "As long as we live under the protection of the Stars and Stripes, we ought to do something to give it attention - at least once in the year."