Documentary telling the story of swing, an obscure form of jazz that became the first worldwide pop phenomenon, inspired the first ever youth culture revolution and became a byword for sexual liberation and teenage excess well before the Swinging Sixties. In the process, swing threw up some of the greatest names in 20th century music, from Louis Armstrong and Duke Ellington to Billie Holiday and Frank Sinatra. The film uses archive and contemporary accounts to shed light on why it endures today.