For its opening program at the Kennedy Center Opera House Wednesday night, the Joffrey Ballet put the accent on its dancers and their youthful scintillation. The choreography, except for James Kudelka's deeply probing "Passage," was mostly lightweight.

Last night, the dancers sparkled as brightly for the company's second program. But with a quite different assortment of ballets, the evening's center of gravity shifted toward the choreography. And at the center of that center stood the Washington premiere of Laura Dean's stunning "Force Field," a work for 20 dancers set to Steve Reich's "Six Pianos."

The work and the performance were accorded a cheering ovation. It isn't always the case that artistic merit and popular approbation go hand in hand, especially with choreography so strenuously demanding of both the cast and the spectators. But the power of "Force Field," as a dance composition and as a kinesthetic torrent, is of such magnitude that it sweeps conventional barriers aside.

"Force Field," which had its world premiere in Iowa a few weeks ago, is the third work Dean has given the Joffrey company, and it's not only the best of them but one of the strongest pieces seen on a ballet stage here in some time. It's as though Dean has brought together all the elements she's been juggling in recent years -- minimalist repetition, geometric patternings, spinning (in all its varieties), balletic positions and moves (like arabesques and sissonnes) and partnering techniques -- and woven them into a grand new synthesis. The faltering compatibility of these ingredients that has marked some of her recent choreography has disappeared here.

The piece is "minimal" now only in the sense of restricting the movement lexicon to reiterated modules, but the number and complexity of those modules -- and their combinations -- far exceed those of her more austere work of the '70s. One senses that Dean has arrived at a new level of understanding of her materials in "Force Field" -- certainly in relation to making work for ballet dancers, as opposed to her own, quite differently trained contemporary group. The payoff is the riveting impact of the work, which speaks for itself.

The impression that Dean was straining the Joffrey dancers to the limit of their mental and physical capacities somehow added to the force of the performance. Part of the thrill was watching the dancers struggling with -- and eventually conquering -- the relentless pulse and its upredictable shifting of gears, the exhausting dynamics, the challenge of staying correctly aligned. The cast, led by Beatriz Rodriquez and Philip Jerry, grew in security as the work progressed, and the final passage, like the gushing forth of a fountain, was truly brilliant.

It needs only to be added that the Laura Dean Dancers and Musicians -- the choreographer's own troupe -- will be performing here tonight and Saturday at the Warner Theatre.

There was unusual choreographic interest as well in "Untitled," the collectively created 1975 work by the Pilobolus troupe that the Joffrey added to its repertoire last year. This piece of grotesquerie, with its full-skirted women rising to ridiculous heights on the shoulders of near-nude men, its mock pregnancies and birthings, and its seamy undercurrents beneath the surface of an "innocent" picnic, never fails to titillate audiences. Its theatrical and gymnastic skills are undeniable, but personally I've always found the work and its subliminal message about the predatory, incestuous and homoerotic instincts of women rather repugnant. Be this as it may, the Joffrey cast -- Rodriguez, Jill Davidson, Jerry, Jerel Hilding, Patrick Corbin and Raymond Perrin, performed it with consummate sophistication.

Also worthy of admiration from a choreographic standpoint was John Cranko's "Jeu de Cartes," the wittily crisp poker game in the form of a dance charade set to a historic Stravinsky score. The piece rather overloaded the program; it might have been seen to better advantage in another context. All the same, Lauren Rouse as the pouty Queen of Hearts, Kim Sagami as the pixie-ish Two of Diamonds and David Palmer as the antic, high-flying Joker were droll and spirited, and the others projected the work's humour nicely.

The evening began with the Washington premiere of Gerald Arpino's "Birthday Variations," a frothy showpiece in traditional style set to selections from Verdi operas. Glenn Edgerton and Dawn Caccamo led the sprightly cast of six.