Swing refers to a rhythmical aspect of jazz, characterized by a forward momentum and elasticity of pulse. During the Swing Era, big bands, with large rhythm, sax and brass sections, became widely popular. By the beginning of the 1930s, the United States was in the midst of the Great Depression. While this era was a rather upsetting time period in American history, the Great Depression positively affected the popularity of Jazz. During this time, big swing bands would play dance music in dance halls. Many Americans went to these dance halls to dance, listen to Jazz and escape the stresses of their daily lives. Dances such as the Lindy Hop and Jitterbug became popular at the time, often accompanied by Jazz instrumentals. While Jazz instrumentals were popular at this time period, during the Swing Era, vocalists used in Jazz pieces became more important and popular. Vocalists like Billie Holiday and Frank Sinatra helped to elevate the popularity of Jazz vocalists. Also occurring at this time, Jazz pieces were just beginning to be recorded. Recordings of Jazz pieces allowed Jazz to reach a larger audience because one no longer had to leave their house in order to listen to Jazz. Additionally, famous Jazz pieces could now be permanently recorded so that they didn’t become lost or forgotten about. Unfortunately, just as Jazz was reaching its peek popularity, the Swing Era seemed to come to a sudden end. On August 1st, 1942, the American Federations of Musicians ordered musicians to stop recording for for record companies. This ban severely limited Jazz musicians. However, several other factors contributed to the end of the Swing Era. For example, by the 1940s, the United States was involved in a total war effort in World War II, this resulted in gas rations that made it difficult and expensive for big bands to travel. Even after the war ended, people just simply didn’t go to dance halls to