Neither musical analysis nor full-blown biography, this impressive book is perhaps best described as cultural history with a biographical focus. As he traces Ellington's "five-decade streak of creativity", from the 1920s to the 60s, Cohen records such breakthroughs as his band's famous Cotton Club residency (which gave it a national following via radio) and the pioneering tours of a still-segregated deep south. And he shows how the Duke's dignity, and his gifts as composer and band leader, made him a bridge between worlds regarded as separate: black and white, highbrow and lowbrow, formulaic chart music and innovative art music. For Cohen, Ellington is not merely an ideal viewfinder through which to watch America changing over the course of the 20th century; he transformed "the nation's racial and cultural landscape". This despite shunning the soapbox and resisting militants' pleas to speak out against racism  Ellington preferred to advance the black cause by being (as the novelist Ralph Ellison put it) "an example and a goal".