African-American music Ruth persuaded a gospel group to sing in a secular setting, the Apollo Theater, with such success that he subsequently arranged gospel caravans that traveled around the country, playing the same venues that rhythm and blues singers had popularized. Meanwhile, jazz performers began to push jazz away from swing, a danceable popular music towards more intricate arrangements, improvisation, and technically challenging forms, culminating in the bebop of Charlie Parker and Dizzy Gillespie, the cool sounds and modal jazz of Miles Davis, and the free jazz of Ornette Coleman and John Coltrane. African-American musicians in the 1940s and 1950s were developing
Tritone substitution Tritone substitution The tritone substitution is one of the most common chord substitutions found in jazz and was the precursor to more complex substitution patterns like Coltrane changes. Tritone substitutions are sometimes used in improvisation—often to create tension during a solo. Though examples of the tritone substitution, known in the classical world as an augmented sixth chord, can be found extensively in classical music since the Renaissance period, they were not heard until much later in jazz by musicians such as Dizzy Gillespie and Charlie Parker in the 1940s, as well as Duke Ellington, Art Tatum, Coleman Hawkins, Roy Eldridge