The odd item in the given list is "melodrama". Poetry, prose, and drama are all literary forms that involve written or spoken language to convey meaning, while melodrama is a type of dramatic work that combines exaggerated emotions with stereotypical characters to create an emotional response from the audience. Unlike poetry, prose, and drama, melodrama relies heavily on spectacle, music, and other theatrical elements to elicit an emotional response, rather than relying solely on the written or spoken word. Therefore, melodrama is not a literary form like the other three items in the list.