Karlheinz Stockhausen
He continued to experiment with new ideas.  Kontakte is a work for piano, percussion and electronic music (the tape has been prepared beforehand).  He composed “live electronic” music beginning in the 1960s.  This means using electronics to change the sound of normal instruments that are amplified.  His operatic cycle Licht was started in 1977 and took him 26 years to complete.  There are seven operas: one for each day of the week. Some of the music for this includes microtonal scales, in which the notes are tuned so that they are less than a semitone apart.