Classical ballet, the most fragile of the performing arts, has been passed on from age to age by means of a chain of personal contacts more like those of the medieval craft guilds than anything in the modern world.

Yet it is one thing to know that this is historically true, and quite another to experience it, startlingly, at an event that amounts to a suburban school recital. That's precisely what happened last night with the performance of "Sleeping Beauty, Act III (Aurora's Wedding)" by the Maryland Youth Ballet in its appearance at the University of the District of Columbia. The enactment was more mysteriously touching than any of its externals could account for.

"Sleeping Beauty" was at once the summit and summation of classicism in ballet, a vision of the most lofty and humane ideals of a civilization. And yet here in microcosm, on the UDC stage, in a production inevitably simplified and makeshift, was the true spirit of the ballet, as rendered by children and budding adults who may well know little or nothing of its past.

For various reasons other than this, the Maryland Youth Ballet is an unusual group, and this was an unusual recital. But the "Sleeping Beauty" alone was a prodigious tribute to Michelle Lees, the prize-winning former dancer who staged it, and to Tensia Fonseca, the troupe's founder and artistic director. As long as there are people around like Fonseca, Lees and their colleagues, the magical transmission of the ballet heritage will continue unimpeded.

That the company and its school are out of the ordinary is attested to by the list of alumni now in the front ranks of the profession, including Fonseca's son Peter, Susan Jaffe and Cheryl Yeager, all prominent dancers with American Ballet Theatre. The latest Wunderkind is 16-year-old Julie Cox, who recently was the only American award winner in Switzerland's Prix de Lausanne competition.

As she showed last night both as Aurora in "Sleeping Beauty" and in the romantic triangle of Eric Hampton's miniature "Nocturne I," Cox is so striking -- in appearance, manners and movement -- that you know after a few moments she's a phenomenal talent, the kind one can wait generations to discover. At the moment, she's like a yearling fawn, nothing but limbs. Still, the ballet discipline, even in her fledgling phase of artistic growth, has removed all trace of gawkiness and replaced it with radiant self-possession. The velvety line of her Aurora would do credit to ballerinas many years her senior, and her arabesque is breathtaking to behold. She sinks into music, moreover, like a dove alighting on a bough.

Plainly, Cox is ready for bigger things, and indeed, she'll soon be moving on to them. In the meantime, her fellow dancers of the Maryland troupe, though of varying degrees of promise and development, reflect in their own way the fine training from which she benefited. Among those who stood out were Heather Ring, Alison Crosby, Beth Arciprete, Lisa Shriver, Cox's partner Thomas Mills and guest dancer Tyler Ingram. The evening began with a charming showcase for younger pupils, "Ballet Daze," choreographed by Fonseca. The program repeats this afternoon, tonight and tomorrow afternoon.