Everyone knows jazz: blues, improvisation, syncopated rhythm, all firmly rooted in Africa via Congo Square in New Orleans. But how have American jazz masters addressed the African ancestry of their music? On this Hip Deep edition, jazz historian Lewis Porter tells the early story of finding the African spirit in Duke Ellington's "Jungle Nights In Harlem" and exotic Africana in the era of Jim Crow. Author Ingrid Monson sheds light on how innovators like Max Roach and Art Blakey channeled Africa in the civil rights era. Poet Amiri Baraka, founder of the Black Arts Movement, talks about jazz as a weapon for change. Pianist Muhal Richard Abrams gives us the experimental sound of the AACM that, through its transcendental "Great Black Music," shattered prevailing ideas of jazz and improvisation. Finally, pianist Jason Moran re-imagines Africa in jazz's present and future with his composition "RAIN." (Produced by Simon Rentner.)