Open Monday through Saturday for lunch noon to 2:30 p.m., for dinner 5:30 p.m. to 9 p.m., for supper until 11:30 p.m. All major credit cards. Reservations. Price: Dinner main dishes, $6.75-$12.45

If Act III is the last act, I won't wait around for curtain calls. La grande restaurant on the roof of the Kennedy Center opened with fanfare, lagged in its second act, and lost much of its audience before Act III, as it is now called. More departures are predicted.

The scenery is still the highlight of this performance -- the Brobdingnagian chandeliers providing enough glitter to compensate for the loss of the early days' celebrity glitter. The tall, ramrod-straight red velvet banquettes are cocoons of privacy, though privacy is no longer needed with the sparse attendance; still, they are impressive expanses of furry crimson. The gold and white damask walls are a gilded break from the primary decoration: all of Washington seen through glass walls as if from Olympus. But nowadays the plates are chipped and the tables lit by Woolworthian glided pierced tin lamps flickering with candles. The overture to this stage set is a table of credit cards, little piles of them, displayed where some restaurants might show off their pastry creations or an hors d'oeuvres still life, in the entry. To speed your departure for the theater, explains the maitre d'hotel, but it looks like a pay-now[WORD ILLEGIBLE] later marketing program.

If they really wanted to speed the departure for the theater, they wouldn't let people sit at tables for 15 minutes before they approached to take a drink order or offer a menu. Even so, the waiters are obviously chosen for their track records, and are able to race you through as many courses as you want to prelude your curtain.

Once you have applauded the restaurant's stage set and marveled at the pace, there is not much to elicit comment. The food is all right. But not at those prices.

No particular expertise is necessary to produce most of the appetizers -- seafood cocktails, mushrooms a la grecque, ham with asparagus. Yet the oysters -- at $3.25 -- were small and slimy, with flavor available only from the tabasco and horse-radish bottles. Chicken liver mousse packed in a little brown custard cup, aspic-glazed and centered with an olive slice, was smooth and rich, but its heavy tarragon perfume did not quite hide its bitter aftertaste. Double chicken consomme tasted like single consomme, and wouldn't do much for you unless you had a cold.

Compliments, however, go to two bit parts. The salad dressing exhibited a Dijon mustard character that is welcome, and the potato croquette was a crunch that burst around an airy potato fluff. The main courses are standard stuff -- sauteed trout, chicken Kiev, steaks and kebabs. Most interesting, if not most successful, is a duck in a dark, sweet-tangy cider sauce with a tangle of apple shreds. Slightly stringy and hardly crisp was the duck, but about what you might expect from a moderate French restaurant in a midwestern town. On that level is a "veal scallopine French style," which means three small veal scallops beaten into submission and sauteed in a pan not hot enough to brown the flour coating before it turns pasty, in a lemony butter pool. In Indianapolis, okay. At the pinnacle of Washington, at $8.50, it can't meet the competition. The tartar steak, served as an after-theater snack, doesn't even try. The meat is spread thinner than the waferthin dark bread on which it is formed, so it is difficult to even report how it tasted; pumpernickel predominated. What was worse, the open face sandwich had been made so far ahead that its edges were curled, the meat turning brown at its perimeter.

The best dessert, your captain may tell you, is a chocolate surprise. The surprise is that it is the best they can do, for it tastes like chocolate crayons melted over vanilla ice cream. The pastry tray presents multicolored constructions held together with gritty buttercream and an excess of sugar.

On the wine list are 44 wines numbered erratically from 102 to 1209, and you have to order by number. No matter, since the list hardly reveals anything further -- no vintages, no growers, no shippers -- and the waiter can't fill you in on any details.

As a neighborhood restaurant, Act III would hold up. But as prelude or epilogue for a gala evening, one that adds $50 a couple once you have had a bottle of wine and tipped the performers, it still needs a rewrite.