The defining spirit and driving force of the AACM, pianist Muhal Richard Abrams set out on his own path more than 40 years ago, believing that compliance with the artistic and economic norms of the jazz world would prevent him from making the choices that most interested him. As the decades passed and those groundbreaking choices influenced generations of players, Abrams remained an iconoclast, avoiding complacence and defying expectations about genre or style. He doesn’t perform or record much these days, but when he does, the rigorous thought behind the music is unmistakable. Later this month Pi Recordings will release his first solo album in three decades, Vision Towards Essence, which captures a totally improvised recital at the Guelph Jazz Festival in 1998. Abrams’s bracing performance comes closer to classical music than to familiar jazz tropes, with dark harmonies and stark counterpoint governed by a sophisticated logic that keeps his constant flow of new ideas from ever seeming merely glib. The music may not exist on paper, but this is the work of a serious composer. Up first today is Reginald R. Robinson on piano, accompanied by the Fulcrum Point New Ragtime Chamber Group; they’ll play selections from Robinson’s work as arranged by Stephen Burns. a 6:30 PM, Pritzker Pavilion, Millennium Park, 100 N. Michigan,312-742-1168. F A –Peter Margasak