They say that poverty must be a suburb of Vienna, so many composers have died in it," Ellen Taaffe Zwilich notes drily. "Well, there have been times when I thought that obscurity must be a suburb of New York."

Like many contemporary American composers, Zwilich lives in New York: the Riverdale section of the Bronx, which is part of New York City but tries to act like a suburb. She also lived in relative obscurity until a fortnight ago, when she won the Pulitzer Prize for music.

At 44 (her birthday is today), Zwilich is the first woman to win the music Pulitzer, which is awarded for composition. "I knew I had been nominated," she says, "but I didn't take it very seriously. I was absolutely blown out of my chair when I heard I'd won."

She has one commercial recording of her chamber music (on the Cambridge label and unobtainable in Washington last week), and her music has been performed throughout the United States and Europe, including the Library of Congress. Her Pulitzer Prize-winning First Symphony (originally titled "Three Movements for Orchestra") was broadcast on National Public Radio in its world premiere performance by Gunther Schuller and the American Composers Orchestra, and was rebroadcast last Sunday. But Zwilich and her neighbors could not hear the repeat broadcast because WNYC in New York had stopped carrying the NPR Sunday Show even before its final performance tomorrow.

In spite of her relatively unknown status before the Pulitzer award, Zwilich has been supporting herself as a composer in recent years, without any income from the kind of teaching and performing work that helps most composers stay alive. "I'm not making a fortune, but I'm doing all right," she says. "Usually, at the end of the year, I find that I've made more money than I thought I would. This is more possible now than it was 10 or 15 years ago. Commission amounts are more realistic, and you can get grants for copying the parts of a new work, which is often a major expense. I'd say that things are improving for composers. The disadvantage of not teaching is that you're insecure. But it's an advantage to have all your eggs in one basket. It's a stimulating thought that if I don't write well it's because I can't; I have plenty of time and no other demands."

Zwilich composes every day on a regular schedule, beginning the first thing in the morning before anything comes up to distract her. She works in a small room of her high-rise apartment, equipped with a piano and two violins for improvisation. She works only on ideas that excite her personally, not on music that she thinks will sell or impress critics and other composers. And she sees no danger that she will run out of ideas: "Just to do everything that I want to do right now, I would have to live to be 200." Talk of prizes and other financial rewards for composing leaves her cold: "It's a privilege to be doing what I'm doing; it can't be measured in those terms."

She refuses to align herself with any school, clique or trend in composing. "Some people who know my last four or five pieces are surprised that I don't join the chorus against serialism, which I'm not at all against," she says. "I think it has some absolutely wonderful ideas. We're living in a time when you can write music and play it and listen to it and not be too self-conscious about it."

Ellen Zwilich grew up in Miami, where her father (an airline pilot) and her mother owned a piano but did not play it. "I sometimes wonder what that piano was doing there," she muses. She began taking piano lessons at 5, followed by lessons in trumpet and violin, but even before any formal training, she was "making things up" at the piano and dreaming of being a composer. In high school, she was a very serious trumpeter, with works like Haydn's Trumpet Concerto in her repertoire, and she composed music for the school band. Her not-very-musical parents "were basically supportive," she says. "They watched in amazement what I was doing" as she enrolled at Florida State University with a major in music education, then switched to a major in composing in her second year. "They worried a little, as parents will, but they didn't interfere."

From Florida State, where the great composer, pianist and conductor Ernst von Dohnanyi was on the music faculty, she moved to New York in 1964. She lived for a while as a free-lance violinist, played in the American Symphony Orchestra under Leopold Stokowski from 1965 to 1972, married violinist Joseph Zwilich of the Metropolitan Opera Orchestra and studied composing at the Juilliard School under Roger Sessions and Elliott Carter.

Her husband died of a heart attack in 1979, shortly after their 10th wedding anniversary. He can still be heard on her only commercial recording, playing a violin sonata that she composed for him to take on a performing tour of Europe. Now she lives alone, dedicating her life mostly to her work. Her hobbies are swimming (she used to do a half-mile a day but has been too busy lately to keep it up) and photography--particularly informal photos of fellow musicians.

Zwilich's style as a composer is contemporary-eclectic. "I don't see any need to choose between Schoenberg and Shostakovich," she says. "I think that people of my age are living at a point where the whole 20th century is ours. I think we have had a glittering array of predecessors: Stravinsky, Barto'k, Berg, Schoenberg, Shostakovich. There is a certain freedom one has at this point, assimilating them all. There is also, to some extent, a jazz influence in my work. I feel pretty free about it."

For her, music is "an intellectual activity--it's nonverbal, but it engages your mind as well as your feelings." But it is not purely intellectual: "I can't say where music comes from. It's a very magical thing . . . I generally hear it in my head, and formal concepts like ABA structure are at best only very limited explanations of what happens. It all has to be conceived in sonic terms. I may plan ahead, the way a serialist does, but when I get into something, I try to let the piece go where it wants to. It sort of takes over."