“Kontakte” (1959-60), Stockhausen’s first piece to use both electronics and traditional instruments together, marks a turning point in his career, when his music was beginning to show the influences of American avant-garde jazz and composers like John Cage. In “Kontakte” live musicians play alongside a tape recording of percussion sounds that have been altered by different electronic devices (i.e. a ring modulator or a reverberator). Stockhausen wanted the musicians to improvise over the prepared tape, but the musicians were at such a loss that Stockhausen eventually had to score the instrumental parts as well.