Lennie Tristano was an influential jazz pianist and composer, known for his innovative approach to improvisation and his role in the development of the cool jazz style. Born on March 19, 1919, in Chicago, Illinois, Tristano's musical career began as a child, studying classical piano before becoming interested in jazz. Moving to New York City in the late 1940s, he formed his own trio and began recording, influencing the evolution of cool jazz through his work with musicians like Lee Konitz, Warne Marsh, and Paul Bley. Tristano's contributions to jazz include his innovative use of polyphony and counterpoint, his development of the head-solo-head structure in jazz improvisation, and his influence on a generation of jazz musicians. He passed away on November 18, 1978.