When Stephen Wade's one-man show -- "Banjo Dancing, or the 48th Annual Squitters Mountain Song, Dance, Folklore Convention and Banjo Contest and How I Lost" -- opened in Chicago in 1979, a review in the Tribune predicted: "If he's willing, he probably could play there forever." "That review was Cinderella," Wade says. Audience capacity grew from 82 to 400 seats, and after 57 weeks the show closed sold out.

Four years ago Wade brought "Banjo Dancing" to Washington. What began as a three-week engagement has become the city's longest-running show, a four-year holdover with no end in sight, and tonight Wade takes the stage of the Arena's Old Vat Room for his 1,000th performance there.

On stage, pounding rhythms with his feet and telling his old-time stories, he comes off as genuine, ingenuous -- even shy -- and very serious about his work. Off stage, sitting in a theater lounge, he comes off as genuine, ingenous -- even shy -- and very serious about his work.

"There's something very sacred about someone spending money to go see you. That's a covenant," says Wade, who literally sweats through each performance, trying to give his best. "It's a little scary . . . but that's cool."

Even after 5 1/2 years? "Every show," he says with a grave nod. "A show can become airborne or earthbound . . . you have to play to the audience, play to the moment. Otherwise it would be miserable to be on stage for two hours, and that's not fair to you guys." And if the audience fails to respond? "My task is to find them," he says. "You sort of have to unlock yourself."

You also have to take care of yourself. "I've only missed two shows in the last five years," he says. "I stay home after work. I don't go out or I wouldn't be able to do this. I try to sleep enough and not damage myself.

" 'Unfortunately,' " he adds, in the tone of an announcer, " 'Tonight, the part of Mr. Wade will be played by Mr. Wade.' "

Wade, 31, began picking banjo 13 years ago, performing for 11 of them. "It's unquestionably true that I love to play banjo," he says. "I play all day long." Or he seeks out other musicians. Cherishing relationships he has had with great banjoists such as W. Fleming Brown, his teacher, and Doc Hopkins, Brown's teacher, his fingers float lovingly over their photos in the album he has pulled from his backpack. Concerned with the preservation of American culture, he has formed a record company to put out records of the old-timers he has on tape. "I've been approached many times to make a record," he says, "but I'm not the kind of person to make a pop record."

Wade's archival work has landed him a position on the board of directors of the National Council for the Traditional Arts, a speech before the annual meeting of the Association of American Archivists, a performance at President Carter's Labor Day picnic and plenty of raw material for a new show, almost completed.

For "Banjo Dancing" he has combined his favorite tunes and tales into a calico quilt of a performance. Using his banjo as a unifying thread, he spins out Mark Twain's whitewashing passage from "Tom Sawyer," a log cabin spook story, the tale of a superdog that outruns a train. He re-creates a 1950s pen salesman's New York spiel. He spouts a piece of tongue-tripping verbiage -- a four-minute version of "Beauty and the Beast" in words nearly all beginning with F -- and includes a Leo Rosten anecdote.

"This stuff is evergreen," Wade says. "It has broad appeal. The Rosten story isn't limited to being Jewish. It's about a man thinking and figuring something out. It's important to see people think . . .

"I draw a lot from scholars like Flannery O'Connor, and I find it very immediately helpful to me as a performer to be looking at paintings . . . the tilt of a head, the lift of a shoulder, the way hands fold and clench. I get a lot of inspiration going to the National Gallery."

Wade has no plans to vanish. Though more than 115 cities have offered him stages, he says, "I don't want to go yet. I'm working on my work."

His eyes sparkle. "What a great job, trying to make people happy!" He picks up his banjo and begins a lively combination of twang and drumming on the head with an African beat. "I can dance to it too," he says, getting up to clog-dance as his fingers fly over the strings.