Ingram Marshall, a minimalist composer known for the mystery and melancholy of his works, which featured sounds as disparate as San Francisco fog horns and Balinese bamboo flutes, died on May 31 in New Haven, Conn. He was 80.

His wife, Veronica Tomasic, said the cause was complications of Parkinson’s disease.

Mr. Marshall was an influential figure in American experimental music, part of a group of composers who, beginning in the 1960s, stripped music down to basic elements of rhythm and tempo and incorporated digital sounds. A self-described “expressivist,” he was known for haunting, mystical works that fused various traditions, among them European Romanticism, Indonesian gamelan and electronics.

“A musical experience should be enveloping,” Mr. Marshall said in a 1996 interview for Yale University’s Oral History of American Music. “Almost in a narcotic way. Not to be zoned out or in a trance exactly, but to be really wrought up in it. If you can do that, I think you’ve done something.”

Mr. Marshall produced a varied body of work, including chamber pieces for renowned ensembles like the Kronos Quartet, brass sextets, choral works and solo guitar pieces. Much of his music blended conventional instruments with prerecorded, computer-manipulated sounds.

“His music was very emotional, but not in a saccharine, neo-Romantic way,” the composer John Adams, a longtime friend, said in an interview. “It was his own very unique, very sentimental style, but sentimental in the very best sense of the word.”

An admirer of Romantic-era composers like Sibelius and Bruckner, Mr. Marshall had a deep knowledge of the Western classical canon that informed his style, even as he veered in new directions.

“He was not afraid of being very direct and expressive,” said Libby Van Cleve, an oboist who directs Yale’s Oral History of American Music, and for whom Mr. Marshall wrote three pieces. “His biggest impact was just having the courage to write such deeply heartfelt and expressive music in the electronic realm.”

Ingram Douglass Marshall was born on May 10, 1942, in suburban Mount Vernon, N.Y., to Harry Reinhard Marshall Sr., a banker, and Bernice (Douglass) Marshall, an amateur pianist.

At the encouragement of his mother, he began singing at a young age and joined a church choir. His interest in music deepened, and in 1964 he graduated with a bachelor’s degree in music from Lake Forest College in Illinois. He later attended Columbia University and then the California Institute of the Arts, where he received a Master of Fine Arts degree in 1971 and taught classes in electronic music.

While at the California Institute, he met several Indonesian performers and became entranced by their music. Intent on immersing himself in Indonesia’s sounds, he secured a Fulbright grant and traveled to the country for four months in 1971.

The visit was a turning point. He soon began incorporating elements of Indonesian culture, including the gambuh, a traditional Balinese flute, into his music. He adopted a more unhurried style, a development he attributed to his immersion in Indonesian music.

“I realized that the ‘zip-and-zap, bleep-and-blap’ kind of formally organized electronic music I had been trying to do simply wasn’t my way,” Mr. Marshall said in the Yale interview, speaking about his experience in Indonesia. “I needed to find a slower, deeper way of approaching electronic music.”

In 1981, Mr. Marshall produced one of his best-known works: “Fog Tropes,” a somber meditation that paired field recordings of foghorns in the San Francisco Bay Area with brass instruments.

“A lot of people are reminded of San Francisco when they hear this piece, but not I,” Mr. Marshall once said. “To me it is just about fog, and being lost in the fog. The brass players should sound as if they were off in a raft floating in the middle of a mist-enshrouded bay.”

Mr. Marshall’s admirers lauded the spiritual quality of his works. Some drew comparisons to the so-called holy minimalists of Eastern Europe, including the prominent Estonian composer Arvo Pärt.

“True, he does not write explicitly liturgical music, nor does he cultivate any priestly airs,” Adam Shatz wrote in a 2001 feature on Mr. Marshall in The New York Times. “But his music is some of the most stirring spiritual art to be found in America today.”

The composer Steve Reich, another friend, said the mystery in Mr. Marshall’s work made it distinct. He described his music as a mix of American spirituality, “impenetrable, mysterious Northern fog and mist,” and gamelan.

“Ingram can’t be pinned down so easily,” Mr. Reich said in an interview. “It’s not just minimalism, or whatever other moniker you want to put onto it, but it’s radiantly intelligent and beautiful.”

After more than 15 years in California, Mr. Marshall returned to the East Coast in 1990, settling in Hamden, Conn. He continued to compose and teach, serving as a part-time lecturer at the Yale School of Music from 2004 to 2014.

Along with his wife, Mr. Marshall is survived by a son, Clement; a daughter from a previous relationship, Juliet Simon; and four grandchildren.

While he was not religious, Mr. Marshall sometimes spoke about the spiritual power of music. He said he hoped that after disasters, artists could help bring understanding to the world.

“Composers, poets and artists always feel useless in the wake of calamity,” he told The Times in 2001. “We are not firemen; we are not philanthropists or inspirational speakers. But I think it is the tragic and calamitous in life that we try to make sense of, and this is the stuff of our lives as artists.”