"Music, often an art/entertainment, is a total social fact whose definitions vary according to era and culture," according to Jean . It is often contrasted with noise. According to musicologist Jean-Jacques Nattiez: "The border between music and noise is always culturally defined—which implies that, even within a single society, this border does not always pass through the same place; in short, there is rarely a consensus ... By all accounts there is no "single" and "intercultural" universal concept defining what music might be" . Given the above demonstration that "there is no limit to the number or the genre of variables that might intervene in a definition of the musical," an organization of definitions and elements is necessary.