A sub-genre is a sub-category of a specific genre, and can apply to literature, music, film, theater, video games, or other forms of art. Genres were created to classify artistic works into descriptive categories, and a sub-genre breaks down those categories into more defined subjects. This concept emerged around 300 B.C.E., when Greek philosophers Aristotle and Plato organized various written works into three categories. Numerous genres have been added since, and the list of subject matter continues to grow. Due to the amount of artistic material in the world today, sub-categories of major topics make searching material easier because it is a well-organized format.
Literature became one of the first topics to be listed into separate genres and sub-genres. Before the sub-genre was introduced there were only a select number of categories to choose from, including romance, horror, thriller, science fiction, and mystery. These broad terms covered the general concept of the written work but lacked the in-depth description of a sub-category. For instance, romance is now separated into a number of categories, including contemporary, erotica, romantic comedy, and young adult. Horror fiction adopted categories such as historical, psychological, and supernatural, and the thriller genre added new subcategories including action, disaster, erotic, legal, and forensic.
Music has also been categorized into types, and the sub-genre specifies these types even further. The major genres of music generally include classical, blues, country, dance, rap, alternative, and easy listening, and the sub-genre helps further explain the different types of music in each category. This concept is extremely useful when a person is searching for a highly specific type of music. Blues music, for instance, has added sub-groups that include Chicago blues, country blues, classic blues, and contemporary blues. Most stores as well as Internet sites use sub-categories to enhance accessibility, which also speeds up the search process by allowing the customer to skip directly to the type of music he or she is interested in.
Film and theater often have similar types of categories as literature because they are both based on written works. Modern technology has also assisted in the growing popularity of sub-genres, and movies can be easily found by specific descriptions as opposed to very generalized categories. Popular movie sites and machines use the sub-genre as a primary search format in which a customer can choose a category such as dark humor or romantic action comedy in order to find a specific movie.