Rhythm and blues and country: setting the stage for rock n" roll. Historical context behind rising popularity of r&b and country. Increase in production/military buildup, aided in recovery from great depression o: military training in southern u. s. o, great migration. Technology: recording and broadcasting created financial opportunities that were not possible before mass culture/media wow. An individual who was jockeying or riding a record toward success o: looking for cheaper alternatives to live performance during great depression, turn to records. One of the first to play records, gospel and jazz. Vinylite: used for waterproofing, other war material. Often in 4/4 (1-2-3-4 = 1 bar of music) Three periods of blues: 1920s - 1940s, mississippi delta, work songs, call-and-response, myth of robert johnson selling his soul to the devil, prominence of guitar - available and cheap in the late 19th century.