The following piece was written by a leading figure of the post-World War 2 German avant-garde. Identify this composer.?

The composer you are referring to is likely Karlheinz Stockhausen. He was a prominent figure in the post-World War II German avant-garde movement, known for his innovative approaches to music composition, including the use of electronic music and spatialization. Stockhausen's work significantly influenced contemporary music and he is often recognized for his philosophical and conceptual contributions to the art form.