Since then, Mr. Sheng has been writing music that straddles both musical worlds, and he has won considerable acclaim, including a $500,000 MacArthur fellowship last year. Occasionally, he draws on Chinese instruments and musical themes in works meant to Exorcise demons from China's historical past.

Having lived through the Cultural Revolution, Mr. Sheng, 46, first won attention in the American musical world with "H'un (Lacerations): In Memoriam 1966-1976," a searing evocation of that brutal time. Now he is putting the finishing touches on "Madame Mao," an opera that will have its premiere at the Santa Fe Opera next summer.

More typically, though, Mr. Sheng's use of Chinese influences is either gracefully nostalgic or simply a part of his cross-cultural language, as in works like "The Stream Flows" for solo violin and "Three Chinese Love Songs," for voice, piano and viola. Even by Mr. Sheng's standards, though, "Silver River" - the quasi-opera that the Lincoln Center Festival is presenting at the John jay College Theater tonight through Sunday - is unusually cross-cultural.

"It's an opera in a sense," Mr. Sheng said,"because there's music going on all the time, and everything that happens in movement, speech or lighting is a music cue. But it's not strictly an opera in Western terms, because there are other elements in it - operatic vocal writing. Chines opera, a speaking role and also dance. I had to ask myself what I could do to make all these things jell, and my solution was to leave each idiom in its own style, without fooling around too much, and to let the underlying music tie those elements together."

"Silver River" is based on a Chinese fable in which the beautiful Goddess-Weaver falls in love with a mortal, Cowherd, to the consternation of her father, the Jade Emperor, who rules the gods. But in his libretto, the playwright David Henry Hwang has given the tale a contemporary American theatrical sensibility - not least through colloquial asides of a wisecracking Golden Buffalo - and has also added some amplifying detail to the story.

The orchestration is mostly Western, but the signature sounds of the pipa (a Chinese lute) and Chinese gongs and cymbals are prominent in its textures. The principal roles, too, cross a few stylistic boundaries. The Cowherd is an operatic baritone. The Jade Emperor sings in the Chinese opera style. The Goddess-Weaver neither speaks nor sings, but is portrayed in the ornate music performed by an onstage pipa player. And the Golden Buffalo, who brings the Goddess-Weaver and the Cowherd together and is then commanded by the Jade Emperor to separate them, is a speaking role.

When Mr. Sheng was commissioned to write the work for performances at the Santa Fe Chamber Music Festival in 1997, his idea was to write "something really small and portable." He had recently met Mr. Hwang in Chicago, where Mr. Sheng was living (he now lives in Ann Arbor, where he teaches at the University of Michigan), and they had agreed to look for a project they could work on together. When Mr. Sheng began thinking about the legend of the Goddess-Weaver and the Cowherd for Santa Fe, he faxed an outline to Mr. Hwang, in New York.

"I didn't know the story, "said the American-born Mr. Hwang, "I think one of the reasons I was attracted to it was that it gave me a chance to educate myself in things I have missed growing up. My mother was born in China and raised in the Philippines, and my father was born in Shanghai. They met in the United States, and they were interested in assimilating, so I was brought up without access to many of these cultural things. I've since learned that it's a very common story."

Best known for his theater pieces, most notably "M. Butterfly," Mr. Hwang also has some operatic experience, having collaborated with Philip Glass on his Metropolitan Opera commission, "The Voyage." (He also wrote the text for Mr. Glas's musical theater work, "1,000 Airplanes on the Roof.") Among his contributions to "Silver River" were plot suggestions that retain the mythic character of the story while adding detail about the characters' motivations. The Goddess-Weaver, for example, is responsible for weaving stars, which bathe the earth in constant light. Night is created when she falls in love with the Cowherd and neglects her duties.

"For me, there's no fun or challenge in just reproducing the story anthropologically," Mr. Hwang said. "What I've tried to do is invent plot details and psychological textures that are true, I hope, to the original story. Some of it has to do with the Jade Emperor's thinking. Does he oppose the Goddess's involvement with the Cowherd simply because of prejudice and chauvinism, or does he have a reasonable point of view? In the original, the Goddess weaves stars, but nothing happens if she stops. Our notion was to give her a certain responsibility for the cosmos, so that when she is seduced by the charms of the human world, there are consequences."

The version of "Silver River" to be performed at the Lincoln Center Festival is actually the second incarnation of the work. After the Santa Fe performances, Mr. Sheng and Mr. Hwang were invited to present the piece at the Spoleto Festival USA in Charleston, S.C. When Nigel Redden, who directs both Spoleto USA and the Lincoln Center Festival, encouraged them to create a new staging, they approached the Singaporean director Ong Keng Sen, who had recently directed a staging of "King Lear" in which each role was recast in a different Asian genre, from Chinese opera to Japanese Noh theater. The performers spoke in their own languages; supertitles gave Shakespeare's English text.

"At first I thought, what a bizarre idea," Mr. Sheng said, "But I got hold of the videotape, and I loved it. And I thought it would be perfect for this, because our division of roles was similar in some ways."

But the discussions with Mr. Ong led to some substantial revisions.

"The first thing he suggested," Mr. Sheng said, "was that because the pipa player represents the Goddess, but is not really an acting role, we should have a dancer as a body double. Then he decided that if the Goddess has a body double, the Cowherd should, too. So we brought a flute player from the pit to the stage. This made for some complications: before, the flutist could be anyone, but now it had to be a male."

He also thought that the Jade Emperor should be presented grandly, so we added a couple of dancers to be his entourage. And he suggested that the Golden Buffalo, which had been a male actor in Santa Fe, should be an African-American actress. So all of that was his idea, and we bought it. And that meant expanding and rewriting, and making some changes in the polt."

The revision was completed in 2000, the year it was performed in Charleston. Since then it has been to Philadelphia and to Singapore, and there is talk of a touring version.

Mr. Sheng, meanwhile, has moved on to other things. In recent years, he has returned regularly to China, where his music is now performed. He said he is comfortable there now, but still feels some bitterness about the Cultural Revolution, feelings that are likely to find a musical outlet in his "Madame Mao" opera, as they did in "H'un".

He is also directing this year's Festival of Contemporary Music at Tanglewood, a week of concerts that opens on Friday. European music has been the heart of the festival in recent years, but Mr. Sheng, with the pianist Ursula Oppens and the doprano Lucy Shelton as chamber music coordinators, is focusing on American works, from Ives, Copland and Cage to Steve Reich, Aaron Jay Kernis and Frank Zappa. A handful of Mr. Sheng's own works figure into the programming as well.

"I don't think I was even thinking of 9/11." Mr. Sheng said. "I just wanted to celebrate American music because it's so rich, so varied, so different. And for the most part, I wanted to look at music of the last 10 or 15 years, although we do have an American classics and mavericks program with some older works."

"I think composers living in this age are very blessed, because we have all kinds of styles available to us. A hundred years ago, composers had certain ways of working. Now we have so many means of expression, from tonal harmony to anything you can imagine, and we can pick and choose the appropriate way. It's very exciting. And one of the things that I think is so important for a composer in America is that there is no agenda here, no official idea of what is stylistically right or wrong."