 The 1940s saw the increased use of blaring horns (including saxophones), shouted lyrics and boogie woogie beats in jazz-based music.During and immediately after World War II, with shortages of fuel and limitations on audiences and available personnel, large jazz bands were less economical and tended to be replaced by smaller combos, using guitars, bass and drums.In the same period, particularly on the West Coast and in the Midwest, the development of jump blues, with its guitar riffs, prominent beats and shouted lyrics, prefigured many later developments.