Others, such as Allan F. Moore, state that "genre" and "style" are two separate terms, and that secondary characteristics such as subject matter can also differentiate between genres. A music genre or subgenre may also be defined by the musical techniques, the cultural context, and the content and spirit of the themes. Geographical origin is sometimes used to identify a music genre, though a single geographical category will often include a wide variety of subgenres. Timothy Laurie argues that, since the early 1980s, "genre has graduated from being a subset of popular music studies to being an almost ubiquitous framework for constituting and evaluating musical research objects".