Many years ago I saw a British black and white film about composers of popular music in the early years of the 20th century. Their songs were not protected by copyright legislation. Because gramophone records then were in their infancy, the composers earned a living by selling sheet music. Their "copyrights" were ignored by maverick sheet peddlers, who did not share their income wih the rightful persons. The film depicted the fate of one unfortunate songwriter who died. The film concludes with the creation of a composer's union. The title? Thanks!