Cecil Taylor, the pioneering free jazz pianist, has died, NPR confirms. He was 89. His cause of death is currently unknown. Born in 1929, Taylor learned to play piano at 6 years old. He performed in swing and R&B groups in the early 1950s before beginning to lead his own band in 1956. That year saw him release his debut album as a bandleader, Jazz Advance—a collection of standards. By the 1960s, Taylor was recording original compositions. He was described in The Penguin Guide to Jazz Recordings as “the most daring of artists” whose music left “tonality and jazz rhythm and structure behind.”

He was massively prolific throughout his career. He collaborated with greats like John Coltrane, the Art Ensemble of Chicago, and Max Roach. He was among the subjects of the 1981 free jazz documentary Imagine the Sound. In addition to his recorded accomplishments, Taylor was also a poet. In 1987, he released an album called Chinampas in which he performed a selection of his poems and accompanied his readings with percussion. His collection Cecil Taylor in Berlin ’88 was reissued in 2015. In 1990, he was named an NEA Jazz master. In 2016, he was celebrated with a retrospective at the Whitney Museum of American Art.

Taylor’s style, often described as avant-garde, was singular. The New York Times’ John Rockwell once described Taylor’s aesthetic in a 1981 review of a Public Theater concert:

He has developed a style that needs in no way bow before the techniques of the great classical virtuosos. His playing is tense and crabbed in posture, full of feverishly hammering passages, dissonant harmonic language and a quite remarkable density of texture. The effect is curiously similar to the densely cerebral classical avant-gardism of the 1950s and ’60s, the period in which Mr. Taylor came to the fore in the world of jazz. To this taste, his music is more inviting than most of that avant-gardism—more energetic and passionate.

Correction: An earlier version of this story stated that Taylor was born in 1930. He was born in 1929.