Mauricio Kagel (born in Buenos Aires, December 24, 1931, died in Cologne, September 18, 2008) was an Argentine composer who has lived in Germany for most of his career. He was most famous for his interest in developing the theatrical side of musical performance. Many of his pieces give specific theatrical instructions to the performers, such as to adopt certain facial expressions while playing, to make their stage entrances in a particular way, to physically interact with other performers and so on.
Robert Ashley may be either of two different artists - an American opera writer or an American video-games journalist and podcaster. A) Robert Ashley, a distinguished figure in American contemporary music, holds an international reputation for his work in new forms of opera and multi-disciplinary projects. His recorded works are acknowledged classics of language in a musical setting. He pioneered opera-for-television.