Genre
Genre (, or ; from French genre [ʒɑ̃ʁ(ə)], "kind" or "sort", from Latin genus (stem gener-), Greek γένος, gés) is any category of literature, music, or other forms of art or entertainment, whether written or spoken, audio or visual, based on some set of stylistic criteria. Genres form by conventions that change over time as new genres are invented and the use of old ones is discontinued. Often, works fit into multiple genres by way of borrowing and recombining these conventions.
Genre began as an absolute classification system for ancient Greek literature. Poetry, prose, and performance each had a specific and calculated style that related to the theme of the story. Speech patterns for comedy would not be appropriate for tragedy, and even actors were restricted to their genre under the assumption that a type of person could tell one type of story best.
In later periods genres proliferated and developed in response to changes in audiences and creators. Genre became a dynamic tool to help the public make sense out of unpredictable art. Because art is often a response to a social state, in that people write/paint/sing/dance about what they know about, the use of genre as a tool must be able to adapt to changing meanings. In fact as far back as ancient Greece, new art forms were emerging that called for the evolution of genre, for example the tragicomedy.