Robert Frost expressed modernist themes through classical, "old-fashioned" structures. In "The Silken Tent", for example, which is written as a sonnet, he explores metaphorically the paradoxical position of women in a changing society - apparently free, but in reality still bound. In "Tuft of Flowers", a series of couplets, he addresses labor, a primary issue in a newly industrialized landscape, and the unifying element of work. Even his blank verse conforms to intricate discipline, with each line carefully metered in classical form. "Out, Out", whose title incidently harkens back to Shakespeare's MacBeth, is written in strict iambic pentameter, and illlustrates the modernist concerns of human worth measured by usefulness in the face of industrialization, and the ultimate loneliness of death.