Bluegrass Breakdown is an expansive foray into the makings of bluegrass. More than any other book of its kind, it gets to the roots of a uniquely American music that is deeply linked to working-class ideals and romanticism.   Robert Cantwell engages the historical background, commercial origins, internal workings, and cultural and social significance of popular, old-time music to provide a unique musicological and sociological perspective. Well versed in the history of the tradition and equally as interested in those who listen to the music as in those who create it, Cantwell links bluegrass to its hillbilly roots in Appalachia and shows how the music was transformed by African American folk traditions, the influence of jazz, ragtime, blues, and country music, and the growth of radio and recording technology.