Something came to life at the end of tonight. Perhaps it was just a chapter in the long and productive life of the American composer Elliott Carter, whose opera "What Next?" was premiered at Berlin's Staatsoper this evening. Or maybe it was a larger chapter in the history of American music.

Just shy of 91 years, Carter has written what he calls his first opera, a one-act musical evocation of an auto accident, its aftermath, and the smug satisfaction that the walking wounded--a k a mankind--take in selfishness and inner preoccupation. It is music without traditional harmony or melody, without the traditional sense of rhythm or pulse, and with a coy and literate libretto (by Paul Griffiths) that lives in the absurdist and directionless world of Samuel Beckett, Eugene Ionesco and Jacques Tati. Almost a century after modernist composers like Arnold Schoenberg began refashioning late romantic music into something that was, paradoxically, both more orderly and more chaotic, Carter has produced the quintessence of everything they hoped to accomplish. The German audience, ranging from old men in tuxedos and monocles to young couples in jeans and bright spandex, gave it a standing ovation, with the traditional European foot-stamping on the historic floorboards.

That wouldn't happen in America. Carter is easily this country's most decorated composer, yet one of its least popular among audiences. He has won the Pulitzer Prize twice, received honorary degrees from the world's most prestigious universities and was the first composer to win the National Medal of the Arts. In Europe, and in Germany in particular, he is both respected and appreciated. The prophet at home, however, has an unbroken track record of alienation in the concert hall despite a long string of critical successes.

Throughout his decades, Carter has been undaunted, willing to be the happy loner. Other composers and programmers have turned increasingly to the comfortable musical world that Schoenberg shattered with his mathematical order, or to infantilized minimalism and folk or pop-derived idioms. Not Carter.

"I still write the music I want to write," Carter said in an interview at intermission. "America has always been a hard nut to crack."

A stylistic descendant of Schoenberg and Charles Ives, Carter looks at music as a series of problems and solutions. Schoenberg "liberated" music from traditional tonality and melody. Carter "liberated" music even further, creating difficult but prismatic rhythmic effects and freeing it from a regular, unchanging sense of pulse. He learned to make rhythm modulate like harmony. Each of his major works--and he's the sort of composer who composes only major works--has taken the complex ordering of disparate materials to dizzying levels. Carter has more than once sent one of his beloved compositions--"orphans," he sometimes calls them--into the world unsure if it would be playable.

"What Next?" is no exception. It is ferociously difficult, with an orchestral texture based, in long passages, on a constant, rapid series of seemingly unrelated notes, an effect that is both unnerving and strangely hypnotic, like listening to a TV channel filled with static. There are only six vocal parts (and no chorus), but each singer lives in a rhythmically unique world. The principal lyric soprano, Rose (Simone Nold), has the most consistently melodic lines, flitting off into soaring vocal lines and birdsong. Baritone Hanno Muller-Brachmann, who sang the part "Harry or Larry," has music to match his personality: an oily stud in sharkskin, swaying constantly to some inner lounge singer. There is a contralto (Hilary Summers), whose music is earthy and robust, a boy alto (Ian Antal), who penetrates the texture with cutting questions, and tenor William Joyner babbles pseudo-Zen nonsense. And there is a dramatic soprano role, Mama (Lynne Dawson), who uses her hefty musical lines in a vain struggle to bring some discipline to this obnoxious brood. These unlikely elements are woven into uncompromisingly complex patterns, with beats subdivided into units of three or five. A singer's line may begin with a single note in the middle of a triplet, or a group of five. The effect, while musically daunting, works theatrically, allowing individual lines to penetrate the clangorous orchestra.

The music world has been saying post-mortems for this kind of music for at least 20 years. The notion of music as a series of difficult problems with difficult solutions seems quaint today. In American opera houses, composers are now turning to classic American literature for inspiration. (Major operas based on F. Scott Fitzgerald's "The Great Gatsby" and Arthur Miller's "A View From the Bridge" will be premiered this season.) And composers rely on musical styles that use tonality and engaging rhythmic patterns like a reward for good audience behavior. A composer like Carter can easily be made to look like, say, an architect who builds a house out of garden rakes and garbage bags. Perhaps it's possible, but will anyone buy it?

Carter's greatest legacy may well be that, ultimately, he doesn't care. The composer came reluctantly, at first, to his new opus. At 90, he takes on new projects cautiously. It took conductor Daniel Barenboim, who led the astonishingly accomplished performance, to coax Carter into approaching the form. And it also took on a promise of a performance at the Staatsoper to convince Carter.

For that, Barenboim deserves special praise. The results of Carter's first foray into the form are overwhelming. In Griffith's dense libretto, Carter has found text ideally suited to his musical style. The story, purposely vague, advances by misunderstandings and mistaken homonyms, yet ultimately coalesces into a sad but often humorous morality tale. As with much of his recent music, a clarity and tenderness lie underneath all the apparent cacophony. An orchestral intermezzo, placed midway in the opera, may be some of the most heartfelt and expressive music Carter has ever written.

But more important, Carter has woven together a mind-boggling number of 20th-century preoccupations: the prison house of language, anxiety and alienation; the futility of all our sexual pawing and grasping; the limits of expression, musical and otherwise. His opera asks, again and again, "What next?" Not just for the dazed and distraught characters onstage, but for music and mankind. Like the burst of stage thunder and banging of trash can lids that opens the work, and like each of his greatest works, it makes the question "What next?" a bit terrifying. If every work is a revolution, where does it all end?

Carter's new opera was paired with Schoenberg's one-act "Von Heute auf Morgen" ("From Today Till Tomorrow"), perhaps its ideal partner. Schoenberg's work is also a domestic opera, about a small family cataclysm and its aftermath. It, too, is a touching morality tale clothed in spiky music. Composed 70 years earlier, when modernism was all about masks and identity, it is still of a piece with Carter's opera--except for the creeping sense that there is nothing underneath the masks. Hearing the two works together, it's clear that modernism was pushed from the stage far too early, before it had exhausted its central themes. Carter has pursued those themes consistently, finding new opportunities for expression along the way.

Thousands of miles from his own country, America's greatest modernist has produced a work that, like the best of Bach, is a summation of a tradition fading into unjustified obscurity.

CAPTION: A survivor hobbles about the wreck in Elliott Carter's "What Next?"

CAPTION: American composer Elliott Carter's new opera has wound up onstage in Germany.