World War II was the first conflict to take place in the age of electronically mass distributed music
Many people in the war listened to radio and long playing records en masse. By 1940, 96.2% of Northeastern American urban households had radio. The lowest American demographic to embrace mass distributed music, Southern rural families, still had 1 radio for every two households.
Similar adoption rates of electronically mass distributed music occurred in Europe. During the Nazi rule, radio ownership in Germany rose from 4 to 16 million households. As the major powers entered the war, millions of citizens had home radio devices that did not exist in the First World War. Also during the pre-war period, sound was introduced to cinema and musicals were very popular.
Therefore, World War II was a unique situation for music and its relationship to warfare. Never before was it possible for not only single songs, but also single recordings of songs to be so widely distributed to the population. Never before had the number of listeners to a single performance (a recording or broadcast production) been so high. Also, never before had states had so much power to determine not only what songs were performed and listened to, but to control the recordings not allowing local people to alter the songs in their own performances. Though local people still sang and produced songs, this form of music faced serious new competition from centralized electronic distributed music.
"Lili Marlene" was the most popular song of World War II with both German and British forces. Based on a German poem, the song was recorded in both English and German versions. The poem was set to music in 1938 and was a hit with troops in the Afrika Korps. Mobile desert combat required a large number of radio units and the British troops in the North African Campaign started to enjoy the song so much that it was quickly translated into English. The song was used throughout the war as not only a popular song, but a propaganda tool.