The document discusses the history of American swing music from the early 20th century through the 1940s-50s. It notes that jazz forms originated from black genres and spread through movies, Broadway, and radio in the 1920s-30s. The record industry boomed early on but collapsed during the Depression, while radio became popular. Big bands featuring brass, reed, and rhythm sections emerged in the 1930s-40s, popularizing swing music. Bandleaders and singers like Benny Goodman and Frank Sinatra became stars. Dancing to swing music in dance halls was also a popular trend through this era.