Michael Hersch seems excruciatingly shy as he fumbles a cassette of one of his latest compositions into the player, after which he stands still as a statue, with his back to his listeners, watching the tape spin around for the entire 15-minute duration of the piece. But if this 27-year-old composer is reticent, his music is anything but.

In the past few years, Hersch, who was born in Washington and raised in Reston, has inspired remarkable--and sometimes ecstatic--excitement in the world of classical music. "There is no doubt in my mind that this extraordinary creator, who already has his own special voice, will be a major force," composer John Corigliano wrote recently. Another esteemed composer, George Rochberg, has called Hersch a "rare and unique talent," gifted with an innate understanding of the "dark places of the human heart."

Ricardo Cyncynates, the assistant concertmaster of the National Symphony Orchestra, nominates Hersch as "by far the most impressive composer that I have had the opportunity of meeting" (the reader should bear in mind that orchestral musicians meet a lot of composers). And John Henry Carton, the chairman of the music faculty at Baltimore's Peabody Conservatory, declared Hersch's work simply "brilliant." "Creation of music such as this would be astonishing for one of any age," he said. "Never before have I had the notion that a young Beethoven was showing me his future."

This is all pretty heady stuff for a young composer--particularly one who had never taken a music lesson until eight years ago. But the excitement is genuine, and Hersch continues to inspire more.

Hersch--tall, lean and poetic-looking, with dark brown eyes that scrupulously avoid excessive contact--is a natural musician, one of the very few such artists who never played an instrument. Indeed, he was all of 19 years old when he started to study music.

"Before that, I'd listen to the radio now and then," Hersch said one recent afternoon during an interview on Manhattan's Upper West Side. "I remember that when I was 5, my pet bird died and I went to the radio, hoping that a song would come on that could sum up my feelings. I kept listening and listening."

Such memories aside, the young Michael Hersch would seem to have shown little interest in music. Instead, as he remembers it, he was pretty much like the other kids in his neighborhood, albeit one laden with a rather melancholy soul. He did his homework, he read books (mostly when they were assigned) and he liked to play sports. One of the few things that set him apart was a natural, if limited, ability with the visual arts. "I've been drawing since I was about 2 or 3 years old, and I can reproduce anything," he said. "But I don't have a single, genuinely creative instinct in the visual arts. All I can do is copy."

By the time he was in his late teens, Hersch had worked in construction, on ranches and in suburban pizza parlors. "My father, Jay Hersch, is a businessman and my mother, Patricia, is a writer," Hersch noted, "and so I was raised with a pretty strong work ethic. I tried out a number of jobs, but becoming a musician really never crossed my mind. That was something my brother did."

As it happens, Jamie Hersch, two years younger than Michael, is a phenomenally gifted brass player and is now the assistant principal hornist in the Singapore Symphony. "It was my brother who got me interested in music," Michael Hersch remembers. "He gave me a videotape of Georg Solti conducting Beethoven's Fifth Symphony." And everything changed.

"It was like someone had opened up a hydrant valve full force inside me, and everything in my whole life came gushing forth," Hersch said. "I didn't know what to make of it. I just kept watching and listening to the tape over and over, hundreds of times." Jamie then gave his brother a theory book; within two weeks, Michael was writing music day and night. By now he has composed some 50-60 hours of music, with the promise of much more to come.

"I guess I'd call my 1993 Piano Fantasy my first real work," he said. "I'd only really been exposed to Bach and Beethoven and a few other composers, so there is a sameness to it. It's grandiloquent and immature, but I recognize my voice. I guess I knew from the beginning what I wanted to say."

After that, music began to fall from Hersch as fruit from an unusually generous tree. By his own estimation, he hit his stride in 1994, when, over the course of a single year, Hersch composed a 50-minute cello sonata, the 45-minute Symphony Concertante for Trumpet and String Orchestra, a 35-40-minute set of piano preludes, a 20-minute set of variations for organ, an unaccompanied violin sonata and his first orchestral piece, a prelude and fugue.

By then he was studying at Peabody, where his principal teacher was Morris Cotel; he has also worked with Corigliano, Rochberg and Christopher Rouse. In 1997, the same year he took his master's degree in Baltimore, he won a Guggenheim Fellowship and admission to the prestigious Tanglewood Music Center. The same year, his music began to be performed regularly: Marin Alsop led the Concordia Orchestra in the premiere of "Elegy" at Lincoln Center in February 1997, and three months later Movement for Orchestra received its world premiere at Carnegie Hall.

Since then have come performances by the Colorado Symphony, the New York Chamber Symphony and the Chamber Music Society of Lincoln Center, among other ensembles. Hersch has been commissioned to write works for the Brooklyn Philharmonic, the Orchestra of St. Luke's and the Pittsburgh Symphony. Most notably, a full-length symphony has been commissioned by the Dallas Symphony Orchestra for a premiere in November.

One of the more extraordinary things about Hersch has been his isolation. By his own admission, until recently he has known very little about what contemporary composers were doing. "All my music used to come from inside me, and I somehow knew the last note of a piece by the time I had written the first," he said. "It was all very internal. But now I'm really interested in what is going on around me--all that fantastic work being done in Europe, for example, and a lot of what is being written at home, too."

Hersch credits his wife, Jennifer Tibbetts, a 24-year-old singer he married last October, with bringing a new stability to his life. "She's beautiful and self-confident and has really pulled me out of being a loner. So much of my music was always so pained, so introverted, with an overlying cloak of sadness. These days, my music is sometimes actually pretty funny!"

To call Hersch's music deeply felt would be to understate the matter considerably; at times, it seems pure feeling--a stream of musical consciousness that wells naturally and inevitably. Hersch has been described as a neo-romantic, which is a fair assessment so far as it goes, in that his music is highly personal and intensely expressive.

Yet he is not to be confused with the tidy, retrogressive composers who have adapted the term "neo-romantic" as a bright label to convince potential audiences that their music won't contain any of those nasty dissonances--or, for that matter, anything else that might demand close attention. On the contrary, when listening to Hersch, one has the sense of a real romantic in the time-honored sense of the word--of a Promethean creator who has been charged with relaying his particular message, while wrestling with demons that all but have him pinned.

Watching Hersch play one of his earlier works, his own piano transcription of an orchestral work called "Recollections of Fear, Hope and Discontent," is instructive. Although the 20-minute composition is only a year old, that is a significant amount of time when one considers how quickly things have moved for its creator. Because it is a transcription, it is impossible to imagine the orchestral colors that would illuminate it in a full performance. But it grabs and maintains one's interest.

Throughout the piece, one hears elements of composers who have long since been accepted into Hersch's own pantheon--Mahler, Shostakovich, Prokofiev, Liszt and some earlier masters. There are plenty of pregnant pauses, sudden flurries of notes, personal appropriations of familiar gestures that seem renewed in Hersch's gifted hands. Above all there is a sense of line; despite some digressions, some rhetorical shifts and some long silences, the listener senses that this is a work with a beginning, a middle and an end, and that everything is somehow joined together.

Hersch has been a natural artist; now he is deep into the process of becoming a conscious one. He combines a mixture of urgency and facility that is dazzling; one suspects that he could improvise literally all day and keep a listener's attention. But now he is learning to live with his music before putting it out there in the world--to compose a little less, perhaps, but to compose more completely.

"Until recently, once I copied something out, I thought that it was automatically the very best way I could say it--that whatever came naturally was the best," he said. "But now I'm learning that all my pieces can be improved and they will be improved if I sit with them for a while and let them settle. It used to be that I just wrote, and that was that. Now I'm learning to tinker, to go over other possibilities in my head, to force myself into fresh discoveries.

"You know, the possibilities really are endless," Hersch reiterated with a smile.

CAPTION: "It used to be that I just wrote," says Michael Hersch. ". . . Now I'm learning to tinker."