During 1956, changes in the sound and sense of much r&b, together with the “musical acculturation” of a substantial section of the white audience, enabled many black artists to cross over into the pop charts with greater regularity and deeper penetration than ever before. But as black rock and roll emerged alongside white rock and roll as a distinct sub-category of Rhythm and Blues, so various forces of resistance to the music intensified their efforts to halt its spread.2