When all sides of its love quadrangle are given full measure, "Coppelia" can be more than just a piece of fluff. In this story of a girl, a doll, and the boy and old man who keep confusing the two, the old man is the key figure -- or should be, if everything is to come out right. For the most part in American Ballet Theatre's revival of the ballet currently on view at the Kennedy Center, Dr. Coppelius -- village meanie and experimental scientist -- has been little more than a cantankerous clown, but last night Gil Boggs, in a brilliant debut, gave the old man a heart, and suddenly "Coppelia" wasn't just another silly ballet anymore.

Boggs gave Coppelius's character several dimensions his predecessors in the role had missed. He was cranky and impatient, and there was a suggestion of a rusty wit in his dealings with the villagers. When he consulted his magic book to find the formulas that just might bring his beloved Coppelia to life, he trembled with the contemplation of it, and his hobbled fantasy dances with his creation suggested a man who had realized his dream -- a beautiful woman who would literally dance to his tune -- a few decades too late. When he realized he'd been tricked, his betrayal was heartbreaking, and all this was accomplished with clarity, economy and a sure sense of timing.

Marianna Tcherkassky was a brave and clever Swanilda; Danilo Radojevic, a very likable Franz. The two also made every point in the story clear and seemed to be having fun as well. Tcherkassky's light, exquisitely phrased dancing was almost as surefooted as ever, and her acting was refreshingly naturalistic. Radojevic's high jumps and perfect finishes aptly represented Franz's high spirits.

Keith Roberts contributed an astounding series of turns in the first act's Mazurka. In the third-act divertissement, Deirdre Carberry gave Aurora energy and style; Julie Kent's Prayer seemed to have been danced on one breath. It seems the new "Coppelia," in the best ABT tradition, can lie placidly in the background to be whatever its stars can make of it.

Sunday night's "Coppelia" was an all-star gala, another ABT tradition. The evening had a flashback quality. Not only the leading dancers -- ABT favorites of the '70s Cynthia Gregory and Fernando Bujones -- but much of the audience seemed to have come from galas gone by. The audience was older and furrier than the usual ballet crowd, and they warmly applauded the stars at their entrances -- a sure sign of people who knew what they wanted when they bought their tickets.

It was a reunion kind of performance. Everybody had fun, but no artistic heights were scaled. Gregory was a gawky Swanilda until the last act, when she turned into a star. Bujones' dancing has lost some of its fabled tautness, but he's still got the strongest rond de jambe in the business, and elevation to spare.

Michael Smuin, an ABT favorite of the '60s, was Dr. Coppelius, and his very funny performance was a compendium of timing and tricks. ABT's current stars Amanda McKerrow, Julio Bocca and Susan Jaffe were rather wasted in the ballet's character dances, though the Mazurka gave Bocca a chance to unleash his phenomenal grand pirouette. Victor Barbee was the tipsy priest, and Cynthia Harvey an enticing Coppelia.