Jacques-Louis Monod, a French composer, conductor, pianist and editor who had a powerful influence on the development of postwar modern music in the United States, died Sept. 21 in Toulouse, France. He was 93.

The cause was a stroke, said Harry Bott, a friend and longtime student.

With the soprano Bethany Beardslee, who became his first wife, Mr. Monod traveled the United States in the early 1950s, presenting the works of Arnold Schoenberg, Alban Berg and Anton Webern, who were then considered the center of the musical avant-garde.

The complicated and highly abstract music, often described as atonal, was mostly unknown and unrecorded in the United States and seemed to have no connection with traditional classical stylings. To audiences in Miami, Rochester, N.Y., and Louisville, among his other stops, it might have seemed like sounds from space.

Mr. Monod made the first recordings of Webern’s Piano Variations and other works for Dial Records, a pioneering label best known for its albums of modern jazz with Charlie Parker, Miles Davis and Max Roach. He founded his own ensemble, Musica Camera, at New York’s Town Hall: the composer Milton Babbitt created his song cycle “Du” for Mr. Monod and Beardslee.

In 1955, he presented the American premiere of Edgard Varese’s “Deserts,” one of the first combinations of electronic and instrumental music, with the composer himself controlling the Ampex tape recorder. His social circle included such luminaries as Igor Stravinsky, Aaron Copland and Glenn Gould.

Daniel Plante, a composer and conductor who worked closely with Mr. Monod, described what made his musicianship distinctive. Taking as an example an early recording of Webern from almost 70 years ago, Plante said Mr. Monod’s performances of the “formidable and, some might say, ‘user-unfriendly’ ” “Five Canons (Opus 16)” showed that “both the high technical standards and musical artistry that Monod later became recognized for in the musical community were there from the beginning.”

“Under Monod’s direction, what is an ungrateful and unwieldy work in most hands becomes graceful and melodic and was performed with ease,” Plante said.

Something similar could be said of Mr. Monod’s own music. Rather than place an emphasis on dissonance and formal complications, his pieces were typified by clarity, poetry, delicacy and a distilled lyricism. He composed sparingly, though, and was fastidious about what he sent out into the world: Some a cappella pieces for chorus, an early composition for organ, a duo for violin and cello, and not much else.

Mr. Monod viewed himself as a perfectionist in all musical matters, and his later conducting appearances were rare. “My experience has proved that you need at least one hour of rehearsal for every minute of music,” he told the New York Times in 1985. “Less than that, and you cannot do justice to the piece.”

“Whenever I prepare for a performance, I think, ‘Maybe this time I’m going to do the piece as it should be done,’ ” he added. “But of course, it cannot be. When you perform a masterpiece, the piece always remains greater than any performance you can give.’’

Jacques-Louis Monod was born in Asnières, near Paris, on Feb. 25, 1927. He came from a distinguished Swiss-French family — two scientist cousins, Daniel Bovet and Jacques Monod, were Nobel Prize winners and another was filmmaker Jean-Luc Godard — and his father was a surgeon.

A child prodigy, he was admitted to the Paris Conservatory when he was 8. He later claimed that the only class he enjoyed was Olivier Messiaen’s analysis and aesthetics course, calling him “the only teacher who bothered to show us actual scores. The others gave us only exercises. It was training in becoming a virtuoso at a certain kind of exercise.’’

In 1944, he met René Leibowitz, a Warsaw-born student of Schoenberg and Webern, an admired conductor, the author of “Schoenberg and His School” and, as Mr. Monod would later put it, “the guru of the 10 or 15 people who wanted to know about that kind of music.” Leibowitz invited Mr. Monod along to America in 1950, where he would stay for the next decade.

In the early 1960s, Mr. Monod spent a few years in London, where he conducted weekly programs on what is now the BBC3 network, mostly of contemporary music. He became increasingly busy as a conductor, and he was engaged to lead Roberto Gerhard’s soundtrack music for the 1963 film “This Sporting Life,” a bleak drama starring Richard Harris as an ambitious rugby player.

“Attentive as ever to instrumental balance, he kept stopping the musicians to correct them,” Plante said. Such delays made the production crew, working on a union clock, concerned about overtime costs. “But then, during one stop, his colleague and friend Georges Auric, no stranger to the world of movie scoring, stepped up to Monod, and suggested he not worry too much about balances, that the engineers would take care of all that.”

Experiences such as these codified Mr. Monod’s disinterest in conducting except under the best possible circumstances. “I realized that going after a conducting career was a way of losing one’s life without having time to read a book or do anything else,” he said in 1985. “I decided life was too short for all that jazz.” So he moved back to the United States and took up a succession of teaching jobs.

“In teaching,” he told the Times, “you’re dealing with the real thing — with discipline, and with absolutes that you are trying to communicate. I enjoy that much more than performing.”

In 1975, he founded the Guild of Composers, which he led for the following 20 years before turning over the duties to Plante, who then ran the group until it folded in 2001, during the financial shortfalls following the 9/11 terrorist attacks. He moved back to France in 2011.

Mr. Monod’s marriage to Beardslee and Margrit Auhagen, a translator, ended in divorce. Survivors include a daughter, Caroline, from his second marriage; and two grandchildren.