The 1920s were a time of wonder and flux, when Australians sensed a world growing smaller, turning faster-and, for some, skittering off balance. American movies, music, and dance brought together what racial lines kept apart. A spirit of youthful rebellion collided with the promise of racial perfectibility, stirring deep anxieties in white nationalists and moral reformers. African-American jazz represented the type of modernism that cosmopolitan Australians...