Muhal Richard Abrams at the 2010 NEA Jazz Masters Awards Ceremony in New York. ( Tom Pich/National Endowment for the Arts)

Muhal Richard Abrams, a pianist and composer who was a major force in avant-garde jazz for more than 50 years and who was a founder of the influential ensemble the Association for the Advancement of Creative Musicians, died Oct. 29 at his home in Manhattan. He was 87.

His daughter, Richarda Abrams, confirmed the death but did not specify the cause.

Mr. Abrams was a largely self-taught musician who worked in traditional jazz and blues idioms before developing a distinctive, if hard-to-define style that pushed music in new directions.

Inspired by the forward-looking music of Ornette Coleman and John Coltrane, Mr. Abrams helped launch the Association for the Advancement of Creative Musicians in 1965. The AACM blended elements of modern classical music with traditional African styles, while rejecting the notion of commercially palatable music.

“The people who decide what will be recorded are the business people, not the artists,” Mr. Abrams told the Chicago Daily News in 1974. “It was, for us, a question of survival — black cultural survival.”

Muhal Richard Abrams performing in 2010. ( Tom Pich/National Endowment for the Arts)

The collective’s early performances took place in churches, exhibition spaces and even day-care facilities. More than a working musical ensemble, the AACM was an expression of spiritual ideals and gave rise to other groups, including the Art Ensemble of Chicago.

Mr. Abrams was sometimes compared with such genre-defying figures as pianist Cecil Taylor and bandleader and composer Sun Ra. He did not accept the term “jazz” as a description of his music.

“I want my music to sound like mine, nobody else’s,” he told the Philadelphia Inquirer in 1998. “What I do is just music. You cannot put labels on musicians. You use any elements you want and create many sorts of moods. It has nothing to do with classical or jazz. It is bigger than that.”

Beginning in the 1960s, Mr. Abrams released more than 20 albums, including “Levels and Degrees of Light” (1967), “Young at Heart, Wise in Time” (1969) and “Things to Come From Those Now Gone” (1975), that cemented his reputation as an innovative pianist and composer. Many leading pianists in modern jazz, including Jason Moran and Craig Taborn, cite him as a key influence.

Mr. Abrams’s compositions had close connections to modern classical music. As a pianist, he placed his notes in almost a painterly fashion, with distinct flourishes and strokes of sound. He and his bandmates often produced the work spontaneously, with a spirit of improvisational freedom that led it to be called free jazz.

Yet there was often a recognizable underlying feeling for the jazz and blues tradition in Mr. Abrams’s music, with sinuous melodies built on blues-based harmonic structures and propulsive swing rhythms.

Throughout the 1960s and 1970s, Mr. Abrams often worked with saxophonist Eddie Harris. His adaptable approach could fit comfortably with mainstream jazz musicians, including drummer Max Roach, trumpeter Art Farmer and saxophonist Sonny Stitt, as well as experimental musicians such as Anthony Braxton, Roscoe Mitchell and Henry Threadgill.

In addition to piano, Mr. Abrams often used the trumpet, trombone, tuba and clarinet in various combinations in his works. His later albums, including “The Hearinga Suite” (1989) and “Blu Blu Blu” (1991), prompted jazz critic Gary Giddins to write that Mr. Abrams “must be accounted a preeminent figure in the development of big band music in the period since the ’60s.”

Richard Lewis Abrams was born Sept. 19, 1930, in Chicago. His father was a handyman, and his mother played piano for enjoyment. As a child he showed little interest in music, beyond being drawn to the sounds coming from the open doors of jazz and blues clubs on Chicago’s South Side.

“They kicked the door open in the summertime, wide open,” he said in a 2009 interview with the National Endowment for the Humanities, “so I would just stand there with my mouth wide open, listening. . . . I had no idea that I would be a musician later.”

He took up the piano at 18 before he joined various blues and jazz groups. At the same time, was drawn to classical compositions and links between mathematics and music.

Building on these ideas, he formed the Experimental Band in the early 1960s, which later led to the AACM. In 1967, Mr. Abrams added “Muhal” to his name, based on his studies of numerology. (He said the word signified “No. 1.”)

He was named a National Endowment for the Arts Jazz Master, the country’s highest honor for jazz musicians, in 2010. He continued to perform until shortly before his death.

Survivors include his wife of more than 55 years, the former Peggy Clark of New York; a daughter, Richarda Abrams of New York; two sisters; four brothers; three grandchildren; and five great-grandchildren. He was predeceased by a son, Richard Abrams Jr.

Mr. Abrams did relatively little experimentation with electronic music, preferring the traditional acoustic sound of the piano.

“You’ve got to have a good sound on the piano, and the piano has to be played from end to end,” he told Keyboard magazine. “As long as I have a good instrument, there’s no telling what I might do.”