Leonard Chess co-founded Chess Records, the pre-eminent blues label of the Fifties and Sixties, with his brother Phil. Originally, the Chess brothers Polish immigrants whose family settled in Chicago formed Aristocrat Records in 1947. The Chess label followed two years later, and with it a mind-boggling flood of blues, R&B and rock and roll talent that included Muddy Waters, Howlin Wolf, Bo Diddley, Chuck Berry, Willie Dixon, Etta James And Little Walter. While Phil focused on jazz, Leonard Chess honed in on roots music, making Chess the greatest repository of black music at mid-century. It was under Chess tutelage that Muddy Waters electric blues fomented a revolution that led directly to rock and roll in the person of Chuck Berry, another Chess artist.