TEN YEARS ago two new shows opened at the Kennedy Center, the Grand T Scene restaurant upstairs as exciting to the food world as Bernstein's "Mass" was to the music world. Claude Bouchet in the kitchen, burgundy velvet and acres of crystal in the dining room, a menu of magnificence created by a French chef of considerable talent. Theatergoers were never to have dined so well within an elevator ride of the evening's entertainment. But the hit was short-lived, and the Kennedy Center restaurants have since served little more than promises. Several managements and name changes later, they remain showy, but restaurants where one eats for convenience rather than by choice.

The current rendition, the Roof Terrace, isn't bad; it is just not likely to serve a meal you will remember past the first act. Crab cakes and pastries are the sleepers on the menu, and prices are moderately high. There is also a cafeteria, with the best self-service view in town, and a little mid-price compromise of a cafe' in between.

The surprise is that in 10 years the Kennedy Center has not become a restaurant neighborhood. Before-theater is slim pickings; after-theater is barren. Instead-of-theater there is Jean-Louis in the Watergate; a meal will cost you more than tickets to the Met, but you will be served lovely little set pieces of Chef Palladin's justly acclaimed nouvelle cuisine. Watergate also has its terrace restaurant, lately refreshed; though I haven't tried the food since its reinvigoration, I can vouch for the chef's pa te'. Les Champs, in the building next door, is a dead ringer for a chain restaurant -- the kind you would guess to be a branch far from the watchful eye of the home office. The Intrigue, up New Hampshire Avenue, is adequate but hardly intriguing. Foggy Bottom Cafe in the River Inn and West End Cafe in the Washington Circle Inn are fresh examples of new American cooking -- small menus with a range from gently cooked fish to grand hamburgers, eminently edible vegetable garnishes and lush salads. Moderate prices and all the appeal of an ingenue.

Even so, the Kennedy Center neighborhood, like that around New York's Lincoln Center, is one where you decide whether to eat rather than where to eat.

With newsworthy restaurants creeping east from Georgetown and west from downtown along Pennsylvania Avenue, however, a few are bound to find themselves, even if accidentally, squeezed south toward the Kennedy Center. Or one day a bit player inhabiting a suite-with-kitchen at the Guest Quarters hotel, where it is rumored that the best food in the neighborhood is to be found after the theater, may just stay on and go public.