This document discusses the origins and evolution of jazz rock and jazz fusion genres. It traces how jazz influenced early rock music through horn sections and jazz-trained musicians. In the 1960s, jazz started to appear more on pop charts through artists like Dave Brubeck and Getz & Gilberto. Two key bands, Blood, Sweat & Tears and Chicago, blended rock with jazz and horns under producer James Guercio. Miles Davis' 1969 album Bitches Brew combined rock and jazz in a revolutionary way, inspiring many fusion artists including Mahavishnu Orchestra, Return to Forever, and Weather Report in the 1970s. The document also examines soul jazz artists and CTI Records' popularization of smooth jazz.