From Mamie Smith and her seminal recording of Crazy Blues in 1920 through the standard makers Robert Johnson, Mississippi John Hurt, and Blind Boy Fuller to contemporary stars such as Robert Cray, Joe Louis Walker, and Kenny Neal -- the musical tradition known as the blues has been long and varied. Rising out of the shared uncertainties of Reconstruction freedom thrust upon succeeding generations of African Americans in the Deep South, this musical genre has found enthusiasts and spawned new artists around the globe, giving birth, in turn, to rock-and-roll. The popular Encyclopedia of the...