Karlheinz Stockhausen (German: [kaʁlˈhaɪnts ˈʃtɔkhaʊzn̩]; 22 August 1928 – 5 December 2007) was a German composer, widely acknowledged by critics as one of the most important (Barrett 1988, 45; Harvey 1975b, 705; Hopkins 1972, 33; Klein 1968, 117) but also controversial (Power 1990, 30) composers of the 20th and early 21st centuries. A critic calls him "one of the great visionaries of 20th-century music" (Hewett 2007). He is known for his groundbreaking work in electronic music, for introducing controlled chance (aleatory techniques or aleatoric musical techniques) into serial composition, and for musical spatialization.
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