Precision dancing epitomizes industrial production lines in the modernist era. The genre previewed the precision and formalism that is more associated with graphics and decorative art of the 1920s. Both a mass choral movement and a popular entertainment specialty, it symbolized good and bad aspects of American culture, and referenced militarism and mechanization to audiences in theatres, picture palaces and motion pictures on both sides of the Atlantic. The moving of large numbers of people in unison can be traced historically to both military manoeuvres and ballet, but the stage specialty is popularly associated with the Tiller Girls, troupes of six to eight short female dancers trained at John Tiller’s studio in Manchester, England in the 1890s. They appeared in extravaganzas, burlesques and pantomimes, as lines of jewels (in Aladdin’s cave) or flowers. A team of Tiller girls appeared in New York as The Original English Pony Ballet in Dolly Dollars (1905), and inspired the inclusion of short dancer precision lines in Broadway and vaudeville musicals and revues. Spurred by the popularity of twin and tandem acts in vaudeville, precision line dancing emerged as a popular, American genre in the 1920s, as vaudeville gave way to Prologues, the short shows that alternated with feature films in the ‘picture palaces’. In the latter format, precision lines became associated with the tallest dancers, whose long legs emphasized unison kicks. They often appeared in newsreels and were featured as aural components of the radio broadcasts emanating from the theatres.