Gunther Schuller wastes no time. The noted American composer sleeps little and occasionally forgets to eat.

“Eight hours every night?” he said to an NPR reporter last year. “Life is too short.”

In fact, when Delores Stevens, artistic director of the Martha’s Vineyard Chamber Music Society, asked him last January to write a piece for this summer’s 40th anniversary concert season, he barely hesitated.

“He asked what kind of piece we wanted, when it was for, and how much we’d pay,” said Dee recently. “One phone call and it was a done deal.”

At almost 85, Gunther Schuller has had time to figure out how to schedule his days. He packs them. They’re full of music, much of which is his own. He responds generously to requests for commissions. In early February 2009, the week the Boston Symphony Orchestra would perform the 25-minute-long work for large orchestra he’d written for them, he was working on two of five other orchestra commissions, including one for the Northwest Bach Festival in Spokane, Wash.

What Dee Stevens asked for was a trio for clarinet, cello and piano, in honor of the chamber music society’s founding group, the Montagnana Trio. Mr. Schuller plays none of these instruments. His father, a violinist with the New York Philharmonic, tried to teach him violin. His mother sat him down for piano lessons. He later tried the flute. He dropped all three, having shown what Boston Globe reporter Joan Anderman described the week of his BSO premiere as a “marked lack of aptitude.” His musical breakthrough came at age 11 when he was noodling around on his baby brother’s birthday xylophone. The elder brother got down on the floor and composed a 30-bar piece for xylophone, flute, violin and piano. He still has the score.

Mr. Schuller did not find his own instrument until he was in his teens. When he discovered the French horn it took over his life. He blew into that horn 18 or 19 hours a day, and flunked out of high school. But he had a life. He joined the Cincinnati Symphony at age 16, and was its principal horn before he turned 17. In 1944, at age 19, he moved to New York and the Metropolitan Opera Orchestra where he stayed until 1959.

Meanwhile he discovered jazz. At one point he announced to his shocked father that Duke Ellington was as great as Beethoven and Mozart. He became as obsessed with jazz as he had been with the horn, and haunted the New York City jazz scene. In postwar New York — he would have been in his 20s — French horns didn’t figure large in jazz ensembles. That is, not until Miles Davis heard Schuller play. The great trumpeter asked the young horn player to sit in with him and his nonet and play a few sessions. The fruit of those sessions was the classic album, The Birth of the Cool.

When he was only 20, and playing with the staid old Metropolitan Opera, he wrote Suite for the unconventional mix of oboe, bassoon, and horn. All three movements of the five-minute piece show a decided jazz influence, especially the engaging, tender Blues. This was 1945, when the blues were being played downtown, and in New Orleans, mostly by jazzmen like Jelly Roll Morton and Bunk Johnson, not uptown at Carnegie Hall. Mr. Schuller was so afraid that a classically-trained oboist who was unfamiliar with the rhythms and tempos of Winin’ Boy Blues and Michigan Water Blues would be tempted to make Schuller’s Blues sound like Bach, that he stipulated in its score that it “should be performed precisely as notated without any rhythmic liberties that the players might otherwise be inclined to take.” Just as French doesn’t sound French spoken with an American accent, the blues doesn’t sound like the blues unless played like the blues. Only when you’re fluent in the blues can you play it your way.

Mr. Schuller did go on to write conventionally scored pieces — two piano concertos, two violin concertos, two horn concertos and concertos for flute, trumpet and viola. But he liked to pick unusual but valid instruments like the alto saxophone, the contrabassoon, the organ and double bass and feature them as solos. In 1980 he wrote Eine Kleine Posaunemusik for trombone and band.

By the early 1960s, Gunther Schuller had given up playing the horn to devote his carefully controlled time to composition. But he never gave up his belief that jazz was as important as classical music and should be taken as seriously. So passionate was this conviction that in 1967, on being appointed president of the venerable New England Conservatory of Music, one block down the street from Boston’s Symphony Hall, he was appalled that the conservatory offered no jazz degree program. There were no jazz degree-granting programs in any postpreparatory music school in the country. Worse, he was speechless on learning that the saxophone was not allowed in the school, even as a classical instrument.

“The first act of my presidency was to declare that we will have a jazz department,” he told Boston Globe reporter Siddartha Mitter last year. He enlisted fellow new colleague, pianist Ran Blake, another jazz aficionado, to help him reach out to Boston communities like Roxbury and Dorchester. Together they tracked down young nonclassical musicians and invited them to study at the conservatory.

Mr. Schuller was a high school dropout who had little familiarity with traditional academic structure or patience for traditional sound-like-the-masters musical pedagogy. What he was looking for was improvisation, that on-the-spot creative freedom that jazz not only allows but demands. He wanted his students to listen to greats like saxophonist Wayne Shorter, to listen to trumpeter Miles Davis, but he didn’t want them to sound like either master.

He also intuited that classical and jazz complemented each other — or had the potential to do so — and saw no reason a classical musician or composer couldn’t swing back and forth between the two. Why shouldn’t a French horn player be as at home with the structure and rhythms of Vivaldi and Charles Ives, Brahms and Schickele, Poulenc and Scott Joplin? Why not create a third way of looking at music? He coined the phrase “third stream” to describe this vantage point, and was central in fostering the marriage of classical music’s structure and the fluidity of jazz.

Asking Gunther Schuller to write a piece for the Martha’s Vineyard Chamber Music Society seemed to artistic director Delores Stevens like a natural choice. The New England Conservatory had just celebrated the 40th anniversary of its jazz program. New York was the scene of Jazz40 with multiple concerts last January. Boston held its commemorative concerts at Jordan Hall this spring. Why not ask him to help us celebrate the chamber music society’s 40th? This master of versatility, who has composed some 200 pieces of new music for chamber groups, opera, orchestras, jazz ensembles, as well as combinations of most of them, could surely come up with a fresh take on a trio for clarinet, cello and piano.

The choice of instruments was informed by the society’s founding musicians, the Montagnana Trio. In 1970, John Gates played the clarinet, his wife Caroline Worthington played the cello, and Dee Stevens played the piano. Forty years is an extraordinarily long time in the life of a musical ensemble and, despite the separate departures of Gates and Worthington, Dee wanted to honor the fact that what they started has continued changed but uninterrupted all these years.

Gunther Schuller got it. In fact, the working title for the piece as he worked on it was Homage to Montagnana Trio. As the piece developed a personality of its own, he changed it to Four Soliloquies. No one knows what it sounds like. Not even the composer has heard it, except in his head. Dee Stevens has no idea what it sounds like.

“I know my part, that’s all,” she said.

That will change the evening of July 12, when Four Soliloquies debuts at the Old Whaling Church in Edgartown. Mr. Schuller will be in the audience. He will have heard Anthony McGill, clarinet, Scott Klucksdahl, cello, and Dee Stevens, piano, in rehearsal over the weekend. Now he will hear what it sounds like in a concert setting, with seats and open windows and an audience in summer linens. He will also hear applause, that instant improvisation which, like laughter, is mankind’s reaction to delight. Can there be a more fitting gift to this supreme weaver of classical and jazz sounds than this burst of spontaneous joy and surprise?