Born in Pittsburgh, he studied piano at an early age, and after a short period of touring he settled in Chicago, where at age twenty he founded his first jazz trio. He has stayed a leader ever since, and except for the rare orchestral gig or hosting a visiting soloist, has worked only with his own groups. The first trio followed the then fashionable example of Nat King Cole, consisting of piano, bass, and guitar. He soon replaced the guitarist with a drummer, and by 1958 he had the perfect combo, in tandem with two equally talented musicians, bassist Israel Crosby and drummer Vernell Fournier, and a permanent job at the Pershing Lounge in Chicago.
Detractors aside, this was an extremely popular group. Jamal had developed a modern jazz approach to the piano that differed from the prevailing bop style, which drew mainly from the example of Bud Powell. Powell concentrated on fluid right hand improvisations that were derived from saxophone or trumpet lines, with sporadic rhythmic jabs from the left hand, consisting of reduced two- or three-note chords. Jamal's approach was more pianistic: he played with both hands, using complex, highly colorful, constantly changing voicings, and his lines were often sparse, leaving space for the other members of the trio. Most important, in contrast to the flowing, often predictable bop flow, Jamal varied his rhythms, creating tension and resolution in a dramatic manner.