MIXED COUPLES by James Prideaux; directed by George Schaefer; scenery by Oliver Smith; lighting by Martin Aronstein; produced by the Kennedy Center and Frederick Brisson; with Julie Harris, Geraldine Page, Rip Torn and Michael Higgins. At the Eisenhower Theater through December 20.

Well, Harris is back and Page has got her. Or vice versa. Or whichever. In any event, if you thought this would be a memorable pairing, you thought right, and if you hoped the vehicle would prove more or less worthy of its passengers, you did not hope in vain.

James Prideaux's "Mixed Couples," which opened last night at the Eisenhower Theater, is a low-keyed comedy about two middle-aged couples who meet in a small, fogbound New Jersey airport -- the year is 1927 -- and fill the time by rehashing their lives and the choices that brought them to where they are. Since the two women used to be married to each other's husbands, there is a lot to rehash.

If all this sounds a little static, it is -- particularly the first act, before the inevitable, and highly entertaining, baring of souls. But the story is secondary, or perhaps teritary. The two key facts are that the two key characters are played by Geraldine Page and Julie Harris, both in complete command of their talents, inborn and acquired.

A look at Who's Who in the Cast suggests that Page, who last appeared here in Tennessee Williams' calamitous "Clothes for a Summer Hotel," has not played much out-and-out comedy. A look at her extraordinary performance in "Mixed Couples" suggests what a loss this has been -- although, on the other hand, to have played more comedy, she would have to have played less of something else. Here, she puts so much into her role as a frumpish, straitlaced housewife of middle years that after some of her quips and double-takes, you want to ask for a slow-motion replay.

A valuable Page-watching tip: Don't take your eyes off her when she finishes a speech. The best has often only just begun. She has a marvelous way of sustaining a moment with a wistful glance, a slow burn or a theater-filling sigh -- and whatever she is doing, it shouldn't be missed.

But this is hard advice to follow when Julie Harris is on stage simultaneously. Harris has a more flamboyant role -- as a bitchy actress with a fondness for fibbing and practical jokery -- but there is nothing crude about her performance. Her tall tales are a particular pleasure, including an account of a dubious dalliance with John Barrymore which she illustrates by caressing here former husband's cheek, to general consternation. "I'm the only woman on my block who's slept with Jack Barrymore," she proclaims gleefully. Then she qualifies her claim: "I think. It's a big block."

In a more down-to-earth fantasy -- and one of many notable passages of give-and-take between Harris and Page -- Harris bemoans her childlessness, and dreams of sitting down to an after-theater supper with an imaginary son. But would it be right to make a child eat so late, asks Page? Her children would love it, Harris retorts; her children would be troupers. And then she gets lost in wistful speculation about those "poor little unborn troupers."

The husbands are played by Rip Torn and Michael Higgins, neither of whom has a great deal to do and each of whom does it perfectly. Higgins, prim and austere as Page's book-bound husband, is a particularly good foil for her, and a fine character in his own right.

There are times when Prideaux seems unable to forgo a bit of wordplay or a bitchy comeback, however forced.But most of the dialogue is rhythmic, graceful and, at its best, energetic enough to keep this gentle play rolling happily along. "You never liked me, did you?" Torn asks Higgins. "I frankly don't remember," says Higgins. "Boy, you're as strange as ever!" says Torn, "No," Higgins retorts, "I'm sure I'm stranger now."

A dab of Pinter. A hint of Ionesco. Very European altogether. In the end, "Mixed Couples" is an old compromise between realism and absurdism, and the characters, while revealing a great deal about real people, are only half-real themselves. An actress who once played Portia but knows not a whit about Shakespeare -- this strains credulity. So does the notion that her ex-husband has, 25 years after their divorce, matured into a scholar when she remembers him as "dumb."

And despite a few references to Coolidge, Lindbergh and the like, the '20s setting seems utterly arbitrary, and the characters utterly free of it. But whatever its frailties, "Mixed Couples" has brought two of America's great stage actresses together, and the fireworks, although quiet, are something to behold.