Herbert Jeffrey "Herbie" Hancock (born April 12, 1940) is an American pianist, keyboardist, bandleader, composer and actor.[1]Starting his career with Donald Byrd, he shortly thereafter joined the Miles Davis Quintet where Hancock helped to redefine the role of a jazz rhythm section and was one of the primary architects of the post-bop sound.[citation needed] Hancock's music is often melodic and accessible; he has had many songs "cross over" and achieve success among pop audiences.