SWING -- In the Kennedy Center Opera House trhough March 30.

It's hard to believe that "Swing," the new musical at the Kennedy Center Opera House, wasn't actually written in the 1940s.

By the Reich Ministry for Culture and Popular Enlightenment.

Wasn't it the enemy who spread the idea that American society was frivolous and decadent, its sense of purpose blasted out by its incessant popular music? And would our side clumsily mistake popular American caricatures for national types?

Yet "Swing" is the latest in a series of American nostalgia trips, written by Conn Fleming with songs by Alfred Uhry and Robert Waldman. It purports to capsulize an era at an interminable dance that begins in the late '30s as a benefit for the Spanish Civil War, and ends up on V-J Day.

The characters remain the same, and don't even change costumes between acts, which is just as well because there was no other way to tell them apart. The women all resemble pin-up posters and Coca Cola advertisements, and the men are dressed like crooners.

There's a married couple arguing about money, a going-steady couple arguing about whether to marry, a wallflower couple who find each other beautiful after removing their glasses and a few other vapid types.Periodically, some bulletin from outside the dance is announced -- Roosevelt has died, or the war is over -- but no ones pays any attention. They're too busy with their petty quarrels, or their trance-like admiration of sounds coming from a center stage bandstand.

All romances are based on immediate availability. "Who's your girl?" "Don't have one." "Who's your guy?" Don't have one." And boom -- love at first sight.

The only interest in the war is that some people consider being in uniform a sexual stimulant.

In this society, what passes for personality is embodied by a leggy brunette heroine, played by Janet Eilber, who occasionally says "I wanna be a movie star," and her rich-boy admirer, played in evening clothes by Robert LuPone, who voices a languid interest in becoming president of the United States, when nothing sexier seems to be working out. Comparatively speaking, this makes them models of strong character and idealistic ambition.

No wonder we lost the war.