In 1962, Richard Abrams, a 32-year-old pianist on the South Side of Chicago, formed a rehearsal group called the Experimental Band. Its purpose was not so much to perform as to provide a laboratory of artistic research and development for young black musicians and composers working in jazz, or what Abrams preferred to call ‘creative music’. Abrams had been electrified by the free jazz revolution launched a few years earlier by Ornette Coleman. As Abrams saw it, the liberation from chord-based improvisation that Coleman had brought about was only a first step. Creative musicians would have to invent new structures to replace the old ones; they would have to re-examine their relationship not only to music, but to sound. Freedom, Coleman's gift, was also a challenge, even a burden: as exhilarating as free jazz was, the hard work of building on its liberties had only begun.

Abrams transformed the Experimental Band into a not-for-profit musicians' collective, the Association for the Advancement of Creative Musicians, or AACM, in 1965. His co-founders were the pianist Jodie Christian, the drummer Steve McCall and the trumpeter Philip Cohran, but Abrams was first among equals, and would outlive them all. The AACM aimed to promote its members’ compositions, to stage concerts of their music, and to provide free training for young people on the South Side. Abrams, who began calling himself Muhal Richard Abrams in 1967, was deeply influenced by the cultural nationalism of the era, but his vision of black music was remarkably expansive, as conveyed by the slogan ‘Great Black Music, Ancient to the Future’. And if members wanted to investigate the ideas of Schoenberg or Cage, they weren’t discouraged on the grounds that it was ‘white’ or alien to the black tradition, so long as they were serious.

Abrams, who died on 29 October, retained his charismatic authority over the AACM long after he moved to New York City in 1977. In his insistence on self-determination and serving the black community of the South Side, Abrams put into practice the ideas of Malcolm X, and of the emerging Black Arts Movement. ‘The black creative artist must survive and persevere in spite of the oppressive forces which prevent black people from reaching the goals attained by other Americans,’ he wrote in Black World in 1973. ‘The AACM intends to show how the disadvantaged and disenfranchised can come together and determine their own strategies for political and economic freedom, thereby determining their own destinies.’

But if black liberation depended on collective organisation, Abrams's ultimate goal was individual emancipation, so that each musician in the AACM could pursue their own vision, whether it was the Art Ensemble of Chicago's mélange of free jazz, pan-African rhythms and Dada; the cerebral structuralism of Anthony Braxton; Henry Threadgill's fiery re-imaginings of Scott Joplin tunes; or the stark lyricism of Wadada Leo Smith. The ideas of Malcolm X may have inspired Abrams to create the AACM, but he espoused a philosophy of artistic freedom that was closer to Walt Whitman.

The trombonist and composer George Lewis, in his magisterial history of the AACM, A Power Stronger Than Itself, writes that Abrams spoke in ‘the tone of a revivalist preacher’ at meetings. ‘Wake yourself up,’ he exhorted members. ‘This is an awakening we're trying to bring about.’ The alto saxophonist and poet Joseph Jarman had recently returned from a tour of duty in Vietnam as a paratrooper when he joined Abrams in the Experimental Band. He was shattered, sometimes unable even to speak, haunted by his involvement in a massacre of women and children in a village suspected of being a Communist hideout. ‘Until I had the first meeting with Abrams,’ he recalled,

I was ‘like all the rest’ of the ‘hip’ ghetto niggers. I was cool, I took dope, I smoked pot etc. I did not care for the life that I had been given. In having the chance to work in the Experimental Band with Richard and the other musicians there, I found the first something with meaning/reason for doing.

Jarman was only seven years younger than Abrams, but looked to him as a father-figure. Even in his early thirties, Abrams gave off the aura of an elder statesman – he had a ‘ministerial presence’, in the words of the historian Ronald Radano. Musicians would often gather at his home on the South Side, where he would give informal lectures on Joseph Schillinger's mathematical system of musical composition, or on numerology. (He was a member of the Rosicrucian Order.) An exacting teacher, he didn’t shy away from what Wadada Leo Smith describes as ‘musical hazing’:

Muhal would test new members by putting you on stage with a band. By the time you would take a solo, the other musicians would leave and stand behind the stage, and you could hear them talking behind the curtain. So what happens to you? First you get pissed off, then you wonder why, and finally you decide to play so hard you're going to drag them back on stage.

Abrams applied his exalted standards to his own work as a pianist and composer. He had started out as a bebop pianist, playing with the saxophonists Dexter Gordon and Sonny Stitt, and the drummer Max Roach, when they passed through Chicago. But he created the Experimental Band, and then the AACM, to push himself beyond what he knew. His first album as a leader, Levels and Degrees of Light, released in 1967, revealed his fascination with traditions far outside jazz tradition. Its centerpiece, ‘The Bird Song’, was a chamber work for reeds, violin, vibraphone, percussion and bird whistles that, over the course of 23 minutes, moved through a variety of impressionistic, otherworldly atmospheres, by turns lush, mysterious and frenetic. It was so free in style and sensibility that ‘jazz’ seemed an inadequate, even pointless description for a new kind of music.

Still, much of Abrams's later work would fit comfortably into the jazz canon, while helping to enlarge it. He didn't have a very supple sense of swing, but he had a deep affinity for the blues, and for ballads. His lyricism was on particularly strong display on Sightsong, a 1976 duet with the bassist Malachi Favors, and the 1975 solo recording Afrisong. In the 1980s and 1990s, he made a series of outstanding big band albums for the Italian label Black Saint, notably The Hearinga Suite and Blu Blu Blu, which come close to Mingus in their melding of black vernacular traditions, and in their brash use of counterpoint. Even in Abrams's most dissonant work, such as the late, mesmerising Vision Towards Essence, there is a strong feeling of balance, serenity and discipline. The leader of Chicago's avant-garde was, at heart, a classicist, a man who valued proportion, order and control.

Abrams’s music has received far less attention than his role in the AACM. The neglect didn't seem to bother him. He was a cagey man who had little interest in wooing – or even making himself available to – critics. ‘For years the mass media scavengers have stolen and feasted on black creativity,’ he wrote in 1973; he preferred not to take part in a dialogue that he saw as contributing to a history of cultural theft. In the early 1990s, when I was a student at Columbia University, I received a small grant to study the AACM. I wrote to Abrams, asking to interview him. ‘The history of the AACM will be written by the AACM,’ he replied. Or, as one of Ornette Coleman’s titles puts it, This Is Our Music.