YOU KNOW the situation. It's Saturday night, Madame Baltin, your latest romantic prey, has become tantalizingly available with the departure of her attendant herr, but you have a lingering engagements with pesky Ida (Carolyn Casanave). Despair not if you are Baron Ferdinand Rommer (Rex D. Hays): just have ever-solicitous Gaston ring with some appropriately vague but familiar explanation--"affairs of state" and all. Cole Porter, you certainly know your noble playboys well.

With its whimsical story line, delightful if substanceless lyrics, and perfect comic mastery, it all seems familiar enough, but even the most devoted Porter afficianados probably will have trouble remembering You Never Know, Conceived by Porter as an intimate "chamber musical" with a small cast and none of the painstakingly choreographed routines so typical of commercialized Broadway, then as now, You Never Know might easily have remained forever unknown. When a debilitating horseback riding accident in 1937 left both of Portar's legs forever crippled, the Shuberts took the production into their own hands. Under their direction, "You Never Know" suffered more creative perversions than even contemporary Hollywood screenwriters would tolerate.

Visions of extravaganzas dancing in their heads and likely tugging at their ledger books, the Shuberts rewrote large portions of the music, inflated the cast tremendously, and lumped in additional songs by other composers. Weighted down by such commercial dross, the show closed after one season and might be remembered now as nothing more than a Trivial Pursuit stumper were it not for the efforts of Paul Lazarus. Working closely with the Porter estate, director Lazarus reconstructed the show from the original manuscript, returning "You Never Know" to its original "chamber musical" conception for the 1982-83 Dorset Theatre Festival in Vermont.

At the Huntington, Lazarus succeeds in entertaining the audience with the predictable but predictably amusing romantic romps of Baron Ferdinand Rommer and his devoted servant and apprentice playboy Gaston. For the Baron, love is a sport--its victories to be savored like any triumph, its game rules as important as in any game, and its old conquests good only for colorful but dispassionate reminiscing. His servant Gaston, his name seemingly synonymous with the command "service" and too often, invoked with the same sensitivity, knows love only from the Baron's recounts and, as he laments, "from an occasional peak through the keyhole every year or so."

Yet Gaston enters the game as a player himself soon enough. Calling to cancel an inconvenient appointment for the Baron opportunity answers, and her name is Maria. Maria herself is only a spectator of Madame Baltin (Lynne Wintersteller), and like Gaston she wants no longer simply to observe life but rather to live it like a lady--"to take two baths a day, go riding, and cheat on her husband in the afternoon."

Dousing herself with her lady's perfume, Maria--"Mimi" to her employers--assumes entirely the identity of her mistress as Gaston likewise plays the Baron. His own evening an unusual disappointment, the real Baron returns home, assumes the role of the servant, and establishes the framework for the ensuing comedy of affected manners.

For all its comic energy, You Never Know repeatedly reminds us just how much we do know. Imagine, if you will, a mere servant attempting to love a real person. You never know, it might work out, but only when the lady or gentleman in question is not really a lady or gentleman. At every opportunity, Porter shows Gaston and Maria unable to fathom the protocol of the Penthouse set.

Left alone with the real Baron, Maria commends his manifest education. "I go to movies twice a week," the Baron responds. How to resist a gentleman's advances without offending, Maria asks the real Baron, presumably her equal. Responds Baron Manners: "Say, 'Not so impetuous, Baron. Not before supper, later.'" Left equally confused by the presents of the class which he has so suddenly affected, Gaston asks for romantic counsel as well. Once again, Baron Manners: "Tell her, 'You are the one to whom I belong body and soul,' and remember 'After supper, it is easier to discuss with a woman the dessert.'"

Obsessed by such mundanities of the rules of love, our lovers could just as easily master the rule laden world of a contemporary singles bar, but their story becomes entertainment through the familiar skill of Porter and the refreshingly polished performances of the small cast. We have come to expect much from Cole Porter, and You Never Know, featuring such familiar tunes as "By Candlelight," "At Long Last Love," and "Let's Misbehave," does not disappoint.

THOUGH the first musical for the relatively new Huntington Company, the production sports a professional polish. Delivering a baritone as rich as his impeccable surroundings, Rex Hays makes a commanding Baron, carrying himself like a true mythical aristocrat and offering entertainment fit for any peer. Even to, Hays cannot rival the performance of Mitchell Greenberg as Gaston, who makes even simple, stereotypical conquest seem lovable if not admirable. Breathing too little personality into her stereotype-fashional character, Donalyn Petrucci offers neither the melodious delivery of Hays nor the charisma of Gaston.

As the show progresses--familiar songs all along, cliches and stereotypes rarely surmounted--the "chamber musical" conception offers us something akin to the one-night stands it so shamelessly portrays. Fun, entertainment, mirth: we get all of this, but nothing more. We know our lovers want their dessert, we suspect some fulfillment of those desires, but is that all?

When the Shubert brothers took on You Never Know, they felt compelled to add a heavy coating of glitz. The result was a near-total disaster. By contrast, the Huntington troupe has remained faithful to Porter's original conception of the play, mounting a production that captures all of Porter's charm and many of his faults--among them, a rather sportsmanlike view of romance.