Heterophony

A heterophonic musical texture is one in which one or more instruments play (or one or more voices sing) a variation on the main melody simultaneously. Usually, this occurs while one instrument plays the melody unadorned. Heterophony is a defining characteristic of much of the world's music, including most traditional East Asian music, which did not have harmony or polyphony before contact with Western music. It was also a characteristic of one tradition of American Hymnody in the 18th and 19th centuries, a tradition called "lining out" in which a song leader would sing a line of a hymn, and the congregation would answer, every member singing in the speed or style of their choice. Most notably, this style was adopted in early New Orleans jazz.