Twenty-one years after it stunned Broadway, "Cabaret" is back, and if there is any doubt in your mind that this was a landmark show, lay it to rest.

By conjuring the sleazy Kit Kat Club out of the darkness that was gathering over Berlin in the 1930s and putting it under the mesmerizing rule of a malevolent emcee with bee-stung lips, the creators of "Cabaret" changed the course of the American musical theater forever.

The setting was not just a haven for the dissolute and the lost, nor were the tawdry songs and dances perpetrated under its roof calculated merely to titillate the jaded. The cabaret and all its equivocal glories stood as a metaphor for Germany itself -- drifting inexorably into the clutches of fascism and shrieking with giddy abandon each time a chorus girl's garter was snapped or a drunk slipped under the table.

It was a brilliant notion then and it remains a brilliant notion now. To see Joel Grey -- the original emcee -- surge out of nowhere and once again welcome the audience to a world of rot masquerading as revelry, is to experience the kind of primal shiver that seizes your heart just before the roller coaster takes its first heady plunge into the void.

Grey is not the only guarantee of authenticity in the pre-Broadway revival that opened last night in the Kennedy Center Opera House. The original creative team -- director Harold Prince, choreographer Ron Field, costumer Patricia Zipprodt -- is at the helm. David Chapman is now responsible for the sets, but he has based his designs on those of the late Boris Aronson. And that celebrated fun-house mirror is in its rightful place at the start of the show, throwing off its distorted images of the audience, even as it will later trap the performers in a nightmarish limbo.

And yet it is not memory playing tricks on you if this is not quite "Cabaret" as you remember it. There has been a considerable amount of tinkering with the show that, for all the boldness it evinced in 1966, still felt compelled to pull a few punches. This production doesn't want to betray the original, but it does want to take into account the greater frankness of our times -- a frankness that was already manifesting itself in the 1972 movie version. A very fine line, not to say a paradoxical one, is being walked here.

The results fall curiously betwixt and between. "Cabaret" is not what it was, but the creators have stopped short of the full-fledged overhaul that might establish the show on a new footing altogether. Under the glittering, grimacing come-hither-if-you-dare fac ade, there's a tug of war going on.

Take, for example, Clifford Bradshaw -- the innocent American writer who stumbles, dazed, into a Berlin ripe with dazzlements. He is no longer the robust heterosexual he was two decades ago. Book writer Joe Masteroff has given him a bisexual history, bringing him at least a step closer to the homosexual realities of the Christopher Isherwood stories that inspired the musical. When Bradshaw originally gave in to Sally Bowles' dithering charms, he did so in the blissful "Why Should I Wake Up?" You won't hear it this time.

Songwriters Fred Ebb and John Kander have replaced it with "Don't Go," a plea of mounting desperation. As Gregg Edelman unleashes his sturdy voice and turbulent emotions in the song, you get the distinct impression that he views Sally as his last heterosexual stand. To lose her is to open the floodgates on his troublesome past. The implication is not unwarranted, but it is not fully explored either. It surfaces indirectly -- a new subtext imprisoned in an old context and struggling to fight its way out.

"Cabaret" never exactly minced words about the Nazis' impending persecution of the Jews. But it minces fewer in the current production, which is not afraid to restore one of Ebb's lyrics, deemed too blunt in 1966. Back then, Grey, you may recall, was dancing with a gorilla in a tutu and foolish hat. "If you could see her through my eyes," he assured us with angelic innocence that curdled into an instant sneer, "she isn't a meeskite at all."

"Meeskite" -- a Yiddish term for ugly duckling -- has been jettisoned. With the implacable savagery that marks his performance as a whole, Grey now assures us that in his kohl-rimmed sight the lumbering gorilla doesn't look "Jewish at all." The directness is indicative of this production's intention to rid "Cabaret" of any leftover traces of compromise and hesitation.

The musical's subplot -- the romance between a timeworn landlady and an aging Jewish fruit seller -- was always its least innovative aspect. As played by Lotte Lenya and Jack Gilford, the characters were sweetly poignant, two incipient fossils, suddenly and briefly made young and foolish by love. Their romance, however, unfolded according to the then-accepted formulas of Rodgers and Hammerstein, the very tradition "Cabaret" was upending so vigorously elsewhere.

This production cuts down on the subplot and eliminates the fruit seller's solo, "Meeskite," which not only served to explain the term, but also established the character as a touchingly cockeyed optimist. There is now a matter-of-factness to the twilight courtship, an underlying reluctance on the part of both participants to abandon the protective anesthesia of despair.

Some of that can be attributed to the perfunctoriness of the performances of Regina Resnik, whose acting skills do not match her beautifully grave singing voice, and Werner Klemperer, who proves a distressingly dull suitor. But some of it, too, I suspect, comes from a conscious decision on Prince's part to attune "Cabaret" to our more cynical times. Only Sally is allowed to wear the rose-colored glasses; the rest of us are presumably too aware of the barbed wire that will soon encircle this society to buy into the old sentimental interlude.

Grey certainly plays the emcee with an aggressiveness that was slower to bare its teeth in 1966. From the outset, he is vividly, poisonously, lethally in control. A lot of the boyish exuberance is gone, replaced by the calculations of a much more manipulative man. The Berlin accent is thick and it wrenches his mouth to one side, as if the vowels were bitter and the consonants stung his lips. He has ceased to be playful in such numbers as "Two Ladies," "The Money Song" or "If You Could See Her." He is perversely, knowingly corrupt -- the self-proclaimed ringmaster of damnation.

There is both a loss and a gain here. Grey has given up the naughty charm with which he once lured audiences into his embrace before tightening his grip on their collective necks. He may have been monstrous, but he was cute, too, and that made for a tantalizing ambiguity. Now the performance is unapologetically garbed in evil. The makeup clings mockingly to his face, the way it does to the flesh of a dowager trying to pass for half her age. Mortality must look something like this. Grey used to take the temperature up with each appearance on the Kit Kat stage. Now he takes it down to a chill.

Although Liza Minnelli never played Sally Bowles on stage -- only in the 1972 film version -- she stamped the role for a generation with her idiosyncratic brand of flamboyance. To Alyson Reed falls the daunting assignment of establishing Sally on her own terms. To a large degree, she succeeds with a leggy bravado and a throaty delivery, attesting to the dear girl's fondness for gin and cigarettes. I cottoned to Reed more and more as the evening went on. If she doesn't send the title song defiantly through the roof, she uses it adroitly to plumb the panic and fear under Sally's devil-may-care stance.

The song has been misused so often over the decades that we tend to forget how bitterly ironic it is in context. Life is a cabaret, old chum, only for the gilded moths flitting from one bright light to the next, and only until the intensity of the heat chars their wings and dashes them to the ground.

That dark vision found its ultimate expression in a series of nightclub numbers that alternately beguiled and repelled with their spangled flash and their leering vulgarity. The creators of "Cabaret" now may want to update some of the evening's particulars. Let them. What is best about the show is what was there from the beginning -- death in cheap clothes, goose-stepping on a nightclub table to the clink of glasses and the lusty laughter of the morally inebriated.

Cabaret , by Joe Masteroff. Music by John Kander; lyrics by Fred Ebb. Directed by Harold Prince. Dances and cabaret numbers staged by Ron Field. Sets, David Chapman; costumes, Patricia Zipprodt; lighting, Marc B. Weiss. With Joel Grey, Alyson Reed, Regina Resnik, Werner Klemperer, David Staller, Nora Mae Lyng, Gregg Edelman. At the Kennedy Center Opera House for four weeks.