Looks at the history of music, discussing ". . . the outsiders and rebels who started musical revolutions but were surpressed while mainstream assimilators who borrowed innovations, diluted their impact, and disguised their sources are too often celbrated . . . and traces the ways outsiders and marginalized groups have repeatedly served as trailblazers of musical expression from ancient times to the jazz, rock, and hip-hop sounds of the present"--Adapted from dust jacket.