20th Century, 1939-1945: As World War II began to rage across Europe and the Pacific, communication technology had spread to most of the world. Radio and recording allowed a unified soundtrack of the conflict shared across continents and oceans. Both sides of the war began to practice the art of propaganda in an effort to inspire their people or demoralize their enemies. Music played an important role in this effort to control the hearts of the populace as each country strove to find their musical voice during the war.