In his book Form in, Douglass distinguishes between form, he lists, and dance as examples of genres from the period. There are varying academic definitions of the term genre itself. Music can be divided into different genres in many different ways the artistic nature of music means that these classifications are subjective and controversial, some genres may overlap. Academics have argued that categorizing music by genre is inaccurate and outdated. It is to be distinguished from musical form and musical style, although in practice these terms are sometimes used interchangeably. A music genre is a conventional category that identifies some pieces of music as belonging to a shared tradition or set of conventions.