The click, click, click of the waiter's tap shoes as he comes over to the table to take orders for drinks during intermission. The smell of the chafing dishes, the candles flickering on every table. The dollop of gravy on the playbill. The pile of shrimp shells on a plate that hasn't been taken away. It's life on the dinner theater circuit and the show's about to begin.

And what a show it is: the musicals, the old tunes, the shows that were hits, on their fourth time around, and all you can eat. There will always be a chicken dish, a fish dish, a steamship round of beef, a salad bar -- just the sort of thing that will hold on a buffet table while 300 people file past.

The audience loves it. For those who've seen tried-and-true musicals only in the movies, here's a chance to see one live. At the moment, "The King and I" is playing at Burn Brae in Burtonsville, "Guys and Dolls" is opening at the Hayloft in Manassas, Lazy Susan Dinner Theater in Woodbridge has "Funny Girl" and "Cabaret" is at Colony 7, off the Baltimore-Washington Parkway.

"It's a suburban institution," says Glenn Gates, owner of the Lazy Susan. "Most of them are located in the suburbs. People don't have to put on long dresses and dark suits to come out.

"It's realy an effortless evening," Gates says. "The patron merely comes to the door and pays his ticket and sits back for five hours. He doesn't have to travel from building to building, worry about parking or much of anything else except enjoying himself.

It's really a nighclub for Middle Amercia."

A voice came over the loud speaker at Toby's in Columbia: "Tables 15 through 20 are now invited to come to our main buffet," the hostess called out. t"Tables 1 through 20 have now all been invited to our main buffet."

Men in shirtsleeves, women in bright dresses with matching teardrop earrings -- a wife hoping aloud that next time her husband would wear a tie -- made their way from their tables down the tiers to the center of the room and the food. Past the lime gelatin teamed with aspic, the scalloped potatoes, the rice pilaf, the rigatoni, as the carbohydrates mounted, past the chicken breasts in a cornstarchy sauce, to -- at last -- a hugh bowl of spiced shrimp. This is what they came for, after all. Followed by roast beef, carved to order by a man who later played clarinet in the ensemble.

Here the hungry hordes ate unabated and were unabashed to return for thirds and fourths, even when the fourth helping was a heaping plate layered entirely with spiced shrimp. "They're small," explained one man, "so you gotta eat a lot of them."

Most of the dinner theaters around town have their buffet tables off in a separate room, and diners wend their way to and from it, but part of the show at Toby's is watching the buffet in the center of the room where the plate-loaders do everything but cart the table away on a forklift truck.

The waiter came by on the run to say that there was apple pie for dessert. He would be performing in the show, and one began to wonder whether he'd last. hWhen the pie was served, each piece was poked through with a tiny American flag on a toothpick. The flags would come in handy.

Having filled their stomachs fit to burst, the cheerful gathering eased back and waited for the transformation: how, indeed, this dinning room would be converted into a theater.

First, there was the little matter of the people on ground level, at large round tables in the four corners of the buffet area that would shortly become a stage. They stayed; and their frowns and laughter became an interesting sideshow when things got slow in the center ring.

The buffet tables were unceremoniously whisked away, leaving a floor bare except for the occasional scalloped potato or discarded cream cup, which a hostess scurried to pick up. The "stage" was swept clean, and two young men took to the floor with mops and carefully swabbed it. Five minutes later, another young man materialized and hand-dried it with towels. It was clear there would be a lot of dancing in this production.

Over the P.A., the call went up that there should be no smoking during the performance: fully two-thirds of the audience clapped. And then, since there would be, during the performance, a great deal of running through exits and entrances and aisles by the performers, we were advised to "attend to any necessaries you have during the show at this time."

Many dinner theaters give this warning, and it always brings a laugh. Good advice, of course. Would love to hear it from the stage of the Kennedy Center.

But, strike up the band! "George M!" was the show, and the intro, mestro. At a front table, a group of leisure-suited gentlemen, white-shoed and rotund and in good spirits, fluttered their apple pie flags as the band hit Yandee Doodle Dandy.

Across the table sat a couple from Arbutus, a suburb of Baltimore. The husband admitted he came for the food, but he had his opinions about the lead, the man who played George M. Cohan: "Aw, he can't sing." It was true, he danced better than he sang, making impressive leaps onto a steamer trunk. His personality fit the part, but his voice fell embarrassingly short on the solos: "Over There!" and "It's a Grand Old Flag." But then, Jimmy Cagney's voice wasn't so great, either, in the movie version.

The woman from Arbutus was having a grand time, and during the intermission confessed, "It's always been a fantasy of mine to perform on the stage like this. My mother claims I was on the stage at the Hippodrome when I was four years old. I love anything mucical."

Musical is the operant word in dinner theaters, and some of them are just made for it.

In fact, the performance of "Cabaret" at Colony 7 is the best that can be said about it. the setting, a slightly shabby room with tables skirting the stage, is perfect for "Cabaret." The audience feels itself part of the show. The Kit-Kat club girls, who doubled as waitresses during the meal, danced enthusiastically, dressed in little black things or little red things, or fringe, and at various times scampered about and tweaked the cheek or stroked the chin of a male customer. Little white-haired gentlemenblushed or smiled, but during intermission on her way into the lobby a grandmother was muttering the word "burlesque" in a certain tone. Like Joel Gray in the movie, the m.c. here played his difficult role very well: from time to time, in dinner theater, there is a gem.

Dinner isn't much, from the potato puffs -- the standard frozen sort -- to the fried chicken, circa early TV diners.

And no one seemed to looking after the diners. One couple returned from from the buffet carrying full plates only to find another couple sitting at their table.

By contrast, it's very clear who's running the Hayloft dinner theater. Frank Matthews, a former submarine officer, opened the place in 1971 in an abandoned furniture factory and a barn, which he joined together. Matthews makes the rounds of the tables to see that everybody's happy; then climbs on stage when the show's about to start, to play stand-up comic.

The Hayloft hires professional actors and actresses, which polishes the show, and you don't have trouble suspending disbelief as happens when your waiter is your actor.

It's the only Actor's Equity dinner theater in the area of about 55 in the country. As for computing how many dinner theaters there are altogether, "That is a total impossibility," says Marvin Poons of the American Dinner Theaters Institute. "There are a lot of amateur groups that work weekends in the Holiday Inn and call themselves a dinner theater. There are others that are here today, gone tomorrow." He sent questionaires out to 85 non-Equity dinner theaters and heard back from only half of them: the other half had gone out of business. His educated guess is that ther are 125 full-time non-Equity dinner theaters in the country.

At the Hayloft, the food is important enough that a photo of the chef appears in the playbill along with those of the actors and actresses. The buffet is quite a spread: The usual beef is flavorful beef, carved under two towering flower-and-ice sculptres; the expected chicken is unexpectedly florentine. And there are more surprises: a cold whole rockfish lying in an elegant sweep; a platter of delicious hummus in a fish shape; tender pieces of pork in a sauce with green pepper, potatoes, black olives and garlic; spinach pasta; a huge baked Alaska for dessert.

And it really pays off. Last year, Matthews said, they had over a hundred thousand customers, most of them repeats.

They come to entertain friends, said Matthews, "and get a chance to talk a lot. But if you're bringing the boss out, after the conversation gets a little dull, there's a play to make it easier. It's great for salesmen.

"Our people are here for the entertainment," he said; "they are not here for education of snob-appeal. It's just pure entertainment."

And they come in droves. Some Sunday matinees, half the audience will be D.C. church groups. During one week in July, the Hayloft was visited by a passel of patent attorneys, an oncology group from a hospital, several garden clubs, the Kiwanis, the Optimists of Front Royal, Parents Without Partners, bowling leagues and the service department of Koons Ford.

They come for birthdays. Caroline McKelvey, an insurance agent who lives in Reston, brought her friend Lem Johnson for his birthday. But this wasn't their first visit: "I don't usually want to go to the theater," Johnson said, "but when I get there I enjoy it." As for all the musicals found at dinner theaters, he said, "I get tired of the same group of people always breaking out in song."

And so, on to the Harlequin dinner theater, where a comedy is playing, "Same Time, Next Year," and the only songs are those piped in during interludes when the scene changes.

Tucked behind a Rockvile shopping center, the Harlequin shares the billing with O'Brien's Pit Barbeque. By coincidence, the high point of the buffet was the barbequed chicken. That and the rice would have sufficed. Otherwise, the kitchen sprinkled pepper too liberally -- on potatoes floating au jus next to the beef, the squash combination, the spinach topped with parmesan -- till everything began to meld. But there's a salad bar and a fresh fruit bar; and a dessert bar offering sweets that all had to be scooped up and piled on tiny little plates: apple betty with peanuts hidden in it; a chocolate mousse-cake-vanilla pudding; and a trifle, heavy on the liqueur and whipped cream, and light on the fruit.

The star of the show is Johnny Holiday, a local radio announcer who's a regular at the Harlequin, and surprisingly his voice sounds different on stage from over the airwaves. He hammed it up, but made a good team with local actress Mary Ellen Nester. There are only two players in "Same Time, Next Year," freeing the serving staff from acting duties. This felicitous occurrence didn't keep the waitress fromgiving off testy vibrations when people didn't order drinks.

Here especially the drinks are really pushed. Before the show began, a waitress carried a try of gaily colored cocktails on stage, described their ingredients and announced that anyone who ordered them would get a free Harlequin glass to keep? The drinks wre a steep $3.95 each. And at intermission, another staffer came forth to talk about the special subscription offer that all the staff touted on their T-shirts.

The intermission itself lasted a good half-hour, a lot of which was taken up paying the hill; in most other dinner theaters you pay when you arrive. A lengthy half-time can turn a responsive, jovial audience into grouches, devastating at a comedy. The crowd here was more urban, younger -- and thinner than the crowd at most of the other dinner theaters.

On a take-your-mother-out-to-dinner-Sunday, the tables were full at Burn Brae, housed in a brick building next to a swimming pool in a development, out Burtonville way. Dark wood paneling softened the camp-dining-hall atmosphere, and a chorus of warbling waiters and waitresses circuited the room in search of birthday girls and boys and anniversary couples to sing to. Cheerful family groups filled tier above tier for a delightful production of "The King and I."

But first things first, and in this case under Tffany Lamps, it was the salad bar in the next room. This was a truly complete and challenging one, with such offerings as fresh spinach, fresh marinated whole green beans and fresh mushrooms. Later there would be breaded eggplant, piled in layers of four by greedy guests; a simple baked chicken, very tender; baked sea trout in excellent shape for chafing-dish fare; a fruit bar sporting half pineapples topped with strawberries. And last, anambitious home-made dessert bar presented a half-dozen kinds of cake, sometimes trying too hard (the spice cake came out tasting like cloves) but reaching perfection with the cherry cheesecake.

The heartwarming "The King and I" aging pretty well. When the King's first wife came out to sing how he's something wonderful, there were sniffles all around. Lady Thiang, played by Katherine Campbell, a real-estate agent,had the best voice of a another one of those gems. The King's chauvinism came through well, but he reminded one of Kojak without the lollipop. A teenage member of the audience noted that when the King came out for a clamorous curtain call, "his mouth was full, and he was chewing. Well, there's another meaning for dinner theater.

The party's over. Crumbs and napkins crush underfoot as the happy crowd departed. Two men recognize each other and compare notes. "We came with 88 people, " one says. "In buses?" "No." he replies. "We put 10 of them in our car."

"I saw it back in February," one satisfied customer in her 60s says, "and it's every bit as good now as it was then."