From the field cries and work chants of Southern Negroes emerged a rich and vital music called the country blues, an intensely personal expression of the pains and pleasures of black life. This music--recorded during the twenties by men like Blind Lemon Jefferson, Big Bill Broonzy, and Robert Johnson--had all but disappeared from memory until the folk music revival of the late 1950's created a new and appreciable audience for the country blues.On...