Orchestral jazz is a jazz genre that developed in New York in the 1920s. Early innovators of the genre, such as Fletcher Henderson and Duke Ellington, include some of the most highly regarded musicians, composers, and arrangers in all of jazz history. The fusion of jazz's rhythmic and instrumental characteristics with the scale and structure of an orchestra, made orchestral jazz distinct from the musical genres that preceded its emergence. Its development contributed both to the popularization of jazz, as well as the critical legitimization of jazz as an art form.