For some years now, a small group of songwriters has been championed as the hope of the American musical theater -- so much so that one of the vaunted handful, William Finn, was compelled to write a satirical song about the situation. Last season, as if to prove that the huzzahs weren't merely hype, Adam Guettel unveiled at Lincoln Center the gorgeous Light in the Piazza, which he'd taken nine years to prepare. And now the much-faster-working Michael John LaChiusa has finally composed the impeccable tuner that cognoscenti have been awaiting with waning patience.

Bernarda Alba is an adaption with truncated title of Federico García Lorca's The House of Bernarda Alba. Directed and choreographed by Graciela Daniele, with whom LaChiusa has collaborated before with mixed results, this 90-minute, intermissionless compression of the hothouse play is absolutely stunning in every possible category, from the stark, dirty-white-walled Christopher Barreca set with 10 straight-back, caned chairs to Toni-Leslie James's primarily black dresses with swirling skirts to Stephen Strawbridge's sometimes blazing lighting to Scott Stauffer's crisp sound. Even the placement of the orchestra, conducted by Deborah Abramson, in a row atop the set -- as if the musicians were notes in a treble clef -- is unusually effective.

The raw material -- and it's surely raw from an emotional standpoint -- is the Lorca classic in which the widow Alba attempts to keep a tight rein on her five quite different daughters in 1930s Spain. To the tyrannical mother's dismay, she ultimately finds that repression backfires. (Lorca is writing allegorically, needless to say.) Meanwhile, her daughters, who have very little in common with the five busy-bee Bennet girls in Jane Austen's Pride and Prejudice, run into conflicts among themselves. Much of their fierce squabbling is over Pepe, the unseen townie whom at least three of the siblings have their eye on.

But plot isn't the point here; passion is, whether expressed or suppressed. LaChiusa and Daniele are determined to illustrate passion as vividly as possible in what is being called a musical but could just as easily be described as a dance piece with singing, an oratorio, or performance art. It's a beautifully seamless fusion of all these influences, and it works from the moment when the 10 cast members enter and sit in the row of chairs placed in front of the upstage wall. The flamenco-like stomping of their feet (flamenco consultant Dionisia Garcia, shoes mostly by Menkes) is as riveting as the "five, six, seven, eight" with which A Chorus Line commands immediate attention.

The insistent stomping also represents LaChiusa at last making a convincing statement of his long-held belief that rhythm in music is every bit as important as melody. He has said that he sought each character's individual rhythm before he began to write, and it sounds as if he means what he said. LaChiusa has also intensely contemplated flamenco tradition without striving to ape it. Beyond that, he's undoubtedly listened to whatever he could locate of the "cante jondo" (or "deep song") that Lorca felt was playing like unheard background music in his plays. Though many of the songs that LaChiusa provided for such projects as Marie Christine, Little Fish, and this season's See What I Wanna See registered as under-developed, all of the songlets in Bernarda Alba seem endemic to the composer-lyricist's unifying purpose.

Director/choreographer Daniele has orchestrated her ensemble with the same precision that Michael Starobin has demonstrated in orchestrating LaChiusa's score. Phylicia Rashad, who's making a career of matriarchal roles, is the focal figure. She brings a grey-haired authority (wigs by Wendy Parson) and strong voice to the role as if devoutly carrying a candelabrum to an altar, but Daniele and LaChiusa have seen to it that each of the 10 performers has the opportunity to step forward. The others are Yolande Bavan, Judith Blazer, Candy Buckley, Nikki M. James, Sally Murphy (recently seen as one of Tevye's five daughters), Daphne Rubin-Vega, Saundra Santiago, Laura Shoop, and Nancy Ticotin. If anyone gets special treatment, it's James, incandescent when she angrily takes stage while the others neatly wield black fans.

Lorca, who understood the music of poetry, steeped his works in music; so it isn't far-fetched to suppose that, had it occurred to him to compose The House of Bernarda Alba as an opera, he would have done so. It's never safe to speculate on how a writer might react to adaptations of his plays, but the temptation is to declare that Lorca would have profoundly appreciated this one. It's even possible that, just as it's now difficult to watch George Bernard Shaw's Pygmalion without hearing the songs that Alan Jay Lerner and Frederick Loewe wrote for My Fair Lady, Michael John LaChiusa's Bernarda Alba will become more popular in this country than Lorca's grim, impassioned play. That's how powerful a work of art it is.