In a city gone nuts for thoroughbred heartbreaker Smarty Jones, the Pennsylvania Ballet is betting on a native-born workhorse of its own.

The 40-member company is celebrating its 40th anniversary, and to mark the occasion, it has given itself that thing most coveted by ballet companies: a new version of an old story ballet. Last Friday at the Academy of Music, it premiered "Swan Lake," an ambitious reach for this midsize troupe better known for doing right by the George Balanchine canon and other short, neoclassical works. In a move as bold (and, depending on your level of cynicism, calculating) as wanting to acquire a "Swan Lake" in the first place, Artistic Director Roy Kaiser hired the much-hailed young choreographer Christopher Wheeldon to "reimagine" the 19th-century classic. The 31-year-old Wheeldon had never staged a full-length ballet before, but as the inventive and acclaimed resident choreographer of the New York City Ballet, he is probably the only person aside from Mark Morris who would attract national attention for remaking a constantly remade classic.

Wheeldon didn't disappoint. His "Swan Lake," which continues through Sunday, is unlike any other. It is bound to be discussed and analyzed for some time, not for what it adds to our understanding of the ballet, but for what it takes away. There is no castle setting to launch Prince Siegfried onto his soul-searching journey. There are no woods, no lake. The swans are unfeathered, and vaguely unclean (their white tutus are lightly smudged). There is no royal ball in the third act, where, instead of encountering an array of prospective brides, the Prince is treated to a striptease and an energetic cancan.

Who can resist the cancan? Among the many anomalies of this production, those knickers-baring showgirls are hardly the most remarkable. What is deeply missed, however, is tha t most simple and poetic element of the ballet: moonlight, and the mood its glow conveys. Wheeldon's concept is novel: The ballet starts in a rehearsal studio, and ends up inside Siegfried's mind. But in discarding so much of the charged romantic atmosphere of the original, his version loses emotional force. More than imaginative design or even ballet technique, it is depth of feeling that separates a great "Swan Lake" from a mediocre one. Unlike the other popular Tchaikovsky ballets -- "The Sleeping Beauty" and "The Nutcracker," neither of which turns on life-and-death issues -- "Swan Lake" is an urgent dispatch about the everlasting balm of love. The work churns with dilemmas. There is the Prince, torn by warring loyalties -- to his mother and his kingdom, and to his own restless heart. And there is the plight of his beloved Odette, her avian transformation part of a spell that only true devotion can break.

Wheeldon's concept preserves the story outline, most of the music and much of the traditional choreography by Marius Petipa and Lev Ivanov. But it presents an unfamiliar picture right at the outset. After the overture's promise of grandeur and importance, the curtain opens on a bare rehearsal studio complete with ballet barre and looming mirror. Ballerinas enter, striking iconic poses from Degas paintings, which, as Wheeldon reminds us, the French impressionist made around the time of "Swan Lake's" creation in Russia. The first act unfolds as a late 1800s ballet troupe's rehearsal of the first act, under the gaze of a cane-thumping ballet master and a top-hatted patron.

As this act ends, the other dancers nonchalantly pack up, leaving their colleague who danced the role of Siegfried alone in the studio. Cue the magic moment, when the music swells with doom, the lights darken and projected images of swans in flight rush across the walls, which have started to recede. There had been nothing to suggest that our prospective Prince Siegfried is unusually obsessed with his role, or is a borderline schizophrenic, but suddenly we must believe that he has entered a dream state, and that what we are now seeing is a product of his fevered imagination. Enter the lovely swan queen Odette with her 18 companions, stepping right into what remains of the ballet studio, where she tells her story of being trapped in feathered form until true love releases her. The smitten prince pledges his heart.

This is the weakest moment of Wheeldon's creation. What ordinarily transpires under overhanging trees and soft light is closed in by those studio walls, which are suspended in midair but still hemming in the space, and the effect is claustrophobic. And with Odette now simply an imagined Odette -- instead of a supernatural fairy-tale Odette, which is somehow easier to buy into -- why should we care about her predicament?

The third act makes a stronger impression. The studio has been transformed into a nightclub (real or imagined? Perhaps a bit of both) full of the fin de siecle demimonde. Enter a stripper, ogled by every gent in the joint. This is a clever echo of the Degas paintings, and their ruthless documentation of the leering patrons who frequented the ballet just to get a look at some leg, or more. In case we didn't get it, a Degas painting is prominently displayed. The cancan ladies are very Toulouse-Lautrec. There is vivid energy here, and color -- greens, blues, flashes of black and gold -- which are a welcome change from the muted grayness of the first two acts. One gets the sense Wheeldon felt freer here to add his own choreography, which is fluid, swift and full of falling and rising domino effects throughout the ensemble. This is a whole new take on the third act, but Wheeldon weaves in the traditional showdown between Siegfried and the seductress Odile, who has been brought in by the evil sorcerer Rothbart (in this fever dream, he is the rich patron from the first-act rehearsal) to trick Siegfried into breaking his vow to Odette. The final act is also marked by some fine original choreography that meshes well with the traditional steps, bringing Siegfried and Odette to an unhappy end. The studio walls descend again as Odette vanishes quite beautifully into the Prince's memory, or into the hinted-at watery background, or wherever unattainable dreams go.

What to make of this approach? It neither wholly succeeds nor entirely fails. Wheeldon, who spoke Saturday at the annual conference of the Dance Critics Association, said he didn't see the point of having the contemporary-oriented Pennsylvania Ballet dance a mini-version of the standard "Swan Lakes," those performed by the Kirov Ballet or his former training ground, England's Royal Ballet. The question, he said, became: "How do you take something that's very well loved and fool around with it?"

If fooling around was his goal, he has succeeded. While this was an uneven attempt at repackaging a masterpiece, it was a noble effort at rethinking the art form, at recalling its origins and its enduring power over dancers and audiences alike.

One feels hopeful for this young talent. The ballet world is still waiting for its Triple Crown winner. This production signals that a strong contender may just be around the bend.

Riolama Lorenzo in the Pennsylvania Ballet production.Riolama Lorenzo and Zachary Hench in the Pennsylvania Ballet's minimalist "Swan Lake."