Avant-Garde is taken from the French for "vanguard," which is the part of the armed forces that always stands at the front of the rest of the army. In the case of music, the avant-garde are those individuals who take music to the next step in development or at least take music on a divergent path. The term was first applied only after World War II. In popular idioms it is a term used to describe or refer to free jazz movements but the meaning remains the same: techniques of expression that are new, innovative and radically different from the tradition or the mainstream. Wagner and Debussy can easily be classified as avant-garde relevant to their time but the term did not enter familiar usage until the advent of Stockhausen.