In Crossing Bar Lines: The Politics and Practices of Black Musical Space James Gordon Williams reframes the nature and purpose of jazz improvisation to illuminate the cultural work being done by five creative musicians between 2005 and 2019. The political thought of five African American improvisers--trumpeters Terence Blanchard and Ambrose Akinmusire, drummers Billy Higgins and Terri Lyne Carrington, and pianist Andrew Hill--is documented...