Next month, Stan Wojewodski Jr. ends his brilliant 14-year tenure as Center Stage's artistic director and heads for New Haven to become the new dean of the Yale School of Drama and the new artistic director of the Yale Repertory Theatre.

If you want a measure of the strength of the institution he leaves behind, go see Center Stage's current production of William Shakespeare's festive and philosophical comedy "Twelfth Night," which runs through May 12. Irene Lewis directs. When Mr. Wojewodski leaves, she will take over as acting artistic director for the 1991-1992 season. Her staging of this comic masterpiece should persuade you that a season ticket at Center Stage will remain one of the best buys in town.

Shakespeare took his title for this play from the 12th night of Christmas. Elizabethans celebrated it as a Feast of Fools which turned everything upside down. For one night, frolic and the wild pursuit of love ruled over stern and sober rectitude.

In that topsy-turvy spirit the play sweeps us through the romantic adventures of some zany residents of Illyria. The Duke Orsino loves the Countess Olivia who cruelly rejects his suit. But when Orsino sends his servant, the boy Cesario, to entreat her to reconsider, Olivia falls immediately and passionately in love with the youth. Cesario, however, is not a boy. He's Viola (spiritedly played by Mia Korf), a shipwrecked young woman who disguised herself as a boy for protection in a strange land.

When Viola joined Orsino's court, however, she fell hopelessly in love with him. But Orsino thinks she's a boy and continues to send her around to Olivia's palace with his futile messages of love for the countess, who also believes Viola is Cesario and ardently pursues her . . . Or him. . . .

Anyway, Viola's twin brother Sebastian then shows up while she's off stage. He doesn't know his sister's around. Of course, Olivia and everybody else thinks he's Cesario and . . .

Meanwhile, a hilarious subplot goes on belowstairs. Olivia's uncle, the drunken reprobate Sir Toby Belch, her clever handmaiden Maria and the delightfully air-headed Sir Andrew Aguecheek lay a plot to trick the Countess Olivia's steward, a puritanical scold named Malvolio, played by J. Michael Flynn. They forge Olivia's handwriting and leave a letter for Malvolio to find. In the funniest scene in the play, Malvolio reads the letter and persuades himself that the countess loves him. Sir Toby and his co-conspirators listen from the audience and in the rafters and comment on Malvolio's self-aggrandizing and self-deluding arrogance.

At one point or another in this play, everything seems upside down or backward. Boys are girls. Fools are wise. Seriousness is folly. The conventional thinking of the real world is madness. Reality is an illusion. And, of course, vice-versa.

Take the shenanigans of Sir Toby and the other subplot characters. Nowhere does Shakespeare so readily invite and require active creative collaboration as in his comic scenes. Directors and actors must reinvent them in order to play to the sense of humor of audiences in every age. In this production the silly antics of Kenneth Gray as Sir Toby, Libby George as Maria and especially William Youmans as the witless Sir Andrew will keep you in stitches.

Yet in the play's upside-down manner, the slapstick subplot carries the deeper, more serious themes which always underlie Shakespeare's comedies. While the main plot light-heartedly untangles the mixed-up lovers, the downstairs struggle against Malvolio moves from the funny forged letter to a grim, bloody, physical torturing of the steward.

The harsh treatment of Malvolio will not amuse a modern audience. During this scene, you can feel the level of discomfort rise in the suddenly quiet theater. But Ms. Lewis emphasizes this shocking, dark underside of the comedy.

Shakespeare had no sympathy for the humorless Malvolio. He represents an alien spirit in Illyria. While everyone else moves toward happiness, harmonious relationships and generosity, Malvolio condemns the playfulness around him and attempts to impose a strict regime. In retaliation, the seemingly harmless comic characters brutally drive him from the countess' place. Indeed, they purge him from the play itself.

The countess's fool, Feste, weaves all the themes, plots and subplots together. Ms. Lewis has added to Feste's role in Shakespeare's script to take advantage of Robert Dorfman's multiple talents as a musician, singer, clown and comedian as well as an actor. He plays his clarinet and introduces the drama with a cabaret-style act of songs and monologue. After the intermission, he brings the audience back into the play with a funny broken medley of great speeches from the Bard's most famous dramas.

Feste remains on stage throughout the drama, even when he has no part in the action -- a detached, ironic and melancholy observer who reminds us to savor love and seize the fleeting moments of mirth in the human drama's relentless interplay of comedy and tragedy. At the very end, Mr. Dorfman's voice carries us off on the haunting verses of the sad song with which Shakespeare closes this comedy: "For the rain it raineth every day."

This impressive and enjoyable production of "Twelfth Night" can assure us that during his tenure in Baltimore, Mr. Wojewodski has built a lot more than the well-deserved personal reputation which has now won him the most prestigious position in the American theater. In the last 14 years, he and Managing Director Peter W. Culman have built Center Stage into what the president of Yale acknowledged as "one of the very best" regional theaters in America.

His selection for the positions in New Haven only enhances the stature of the institution he leaves behind in Baltimore.

Tim Baker is an attorney who writes from Columbia.