THE PROBLEM of a ballet such as Sleeping Beauty is not to make the audience believe the fantasy, but to make us not mind that we don't believe it. The dancing doesn't have to carry it alone--after all, this pull-out-all-the-stops Imperial Russian classic, complete with Tchaikovsky score and choreography by the legendary Marius Petipa, is nothing if not an occasion for bravura theatrical spectacle. The dance comes like expensive chocolates wrapped in gold foil: we're supposed to enjoy the package almost as much as the contents.

As sheer spectacle, the Boston Ballet's third annual Sleeping Beauty, which closed last night, succeeded lusciously. Peter Farmer decked out the Fairies in stained-glass blues and greens, as peasants and the Prince's hunting party cavorted in the golds and reds of a New England autumn, and the courtiers looked as though they'd just stepped off a wedding cake, with popsicle-orange feathers bobbing on their bewigged heads. And the decor, especially in the second act, atoned for a flock of balletic bumbles. The ingenious use of layered, semi-transparent drop scrims melted the bright grove of the hunting party into a blue dream-world, then into the cobwebby forest of enchanted sleep.

But if the splendid spectacle of Sleeping Beauty is the well-wrought setting, the dancing must sustain the mood of enchantment. In Sleeping Beauty this is an unusually tricky business, because little of the ensemble choreography is inherently interesting. The delight of such an old-fashioned approach as Sleeping Beauty's must arise from its sense of harmony and proportion; anything that blurs the clean multiplicity of geometric form betrays either conceptual incoherence, or simply a sloppy job.

Whatever the reason, the Boston Ballet falls short too much of the time. At worst, the edges were fuzzy, like a photograph out of focus--one dancer among several off the music by a glaring beat or two, four dancers in a line with legs extended at four different levels. More often, what was missing was not so much technique as imaginative energy. Nothing in particular distinguished several perfectly competent dancers in the first act from perfectly competent performers in any of a dozen other balletic roles. If anyone knew they were the gift-bearing Fairies, it was thanks to the program notes.

In fairness, there were one or two enchanting moments. The second act consisted mainly of a lengthy dream-sequence where the Princess Aurora and her attendant nymphs danced before the bedazzled Prince. Here the ensemble choreography abandoned the conventional interlocking straight lines, and worked a tapestry of fluid configurations. Dancers bordered the stage in an open rectangle, clustered in a small circle, dipped into a deepening zigzag, or fell to the floor in a smooth oval, their long gowns floating out around them like water lily-pads. When the curtain fell, the patterns lingered in the mind like a figure-skater's traces on ice.

That is the effect that solo dancing should have. When it worked in this performance, it was usually because Elaine Bauer danced Princess Aurora (she alternated in the title role with Laura Young and Durine Alinova). Elegant, long-limbed and lean as a grasshopper, Bauer is easily the finest ballerina Boston's got. She is not a great dancer: the flow of near-perfect form is missing, and sometimes she moves with an awkward detachment from her body, hands and feet stiff as saucers. But unlike Laura Young, for example (who danced a typically colorless Princess Florise), Bauer focuses her interpretations with clarity and quiet presence, her body usually locating each pose right where it ought to be.

Bauer's role in Sleeping Beauty includes one of the most infernally difficult sequences in the classical repertoire, the so-called Rose Adagio. It is a moment of psychological depth that is rare in 19th-century ballet. The princess stands poised on her 16th birthday between childhood and adulthood, between the parents whose presence she acknowledges reverently and the four suitors who dance with her in turn, between the festive court around her and the unfolding self-awareness within. Twice during the course of the Adagio, the ballerina must balance on one pointed toe for several minutes as she takes each partner's hand in turn, holds it for a moment, releases it to raise both arms, then graciously takes the hand of the next waiting suitor. In the end, she releases the fourth partner's hand to bloom into an unsupported arabesque, in the most radiant moment of the entire ballet.

IT IS ALMOST impossible to perform this particular balancing sequence really well, and Bauer went about it with visible tension. She almost grabbed her partners' hands, and the final arabesque expressed not so much a triumphant affirmation as a sigh of relief for everyone in the auditorium. In spite of that, her Aurora in this scene and elsewhere was delicate and endearing, each meticulously careful gesture hinting at the hesitance of the not-quite-grownup child.

Aurora's is the only solo role that permits any real dramatic subtlety; the other soloists are either stock characters or vehicles of sprightly choreography, with only the vaguest relations to plot. Anamarie Sarazin's Evil Fairy was a gratifyingly serpentine siren, complete with green dragon wings, gaudy sequins and decadent black stockings a la Toulouse-Lautrec; the wedding guests, from Tom Thumb (Tony Catanzaro) to a White Cat (Debra Mili) were equally charming and improbable.

David Brown's role as the Prince suffers from the usual handicaps of male leads in traditional ballet--most of the time he was little more than a supportive ornament to his ballerina, sort of a graceful coat-rack. That is no excuse for laziness, however, especially during his own solos. Brown has considerable strength, but instead of the effortlessness of the great dancer he moved with an air of nonchalance, as though it really wasn't worth his while to exert much energy or to smooth out the rough edges in his technique.

LUCKILY, Sleeping Beauty depends far more on the heroine than on her prince, and in the Boston production Elaine Bauer and glowing theatrical spectacle managed to tip the balance between ho-hum and lovely, creating a delightful evening from what might have been an embarrassing antique.

Still, the performance remained surprisingly transparent. It showed the Company's individuality only in their weaknesses: the choreographic banality, the ragged ensemble work, the inconsistent quality of the soloists. Beyond that, this charming and classically faithful Sleeping Beauty could have been anyone's Sleeping Beauty. The only positive statement it made about the Boston company was that the performers can bring a timeless classic off well, leaving open the question of whether New England's most important ballet ensemble has yet found an identity of its own.