60年代到70年代，以凯奇为首的作曲家们已经探索尽了绝大部分的类似这样'极端行为艺术'点子。他们创作生涯的结束标志着二战时期到70年代的'现代主义/先锋派/前卫派'盛期的结束。80年代后，随着1 电子音乐 2 流行爵士 3 新浪漫主义音乐的蓬勃发展，这种风格走向衰落，音乐创新回归到了传统听觉范畴内。
Kagel was born in Buenos Aires, Argentina, into a Jewish family which fled from Russia in the 1920s (Anon. n.d.). He studied music, history of literature, and philosophy in Buenos Aires (Grimshaw 2009). In 1957 he came as a scholar to Cologne, Germany, where he lived until his death.
From 1960–66 and 1972–76, he taught at the International Summer School at Darmstadt (Attinello 2001).
He taught at the State University of New York at Buffalo from 1964 to 1965 as Slee Professor of music theory and at the Berlin Film and Television Academy as a visiting lecturer. He served as director of courses for new music in Gothenburg and Cologne (Attinello 2001). He was professor for new music theatre at the Cologne Conservatory from 1974 to 1997.
Invited by Walter Fink, he was the second composer featured in the annual Komponistenporträt of the Rheingau Musik Festival in 1991. In 2000 he received the Ernst von Siemens Music Prize.
Among his students were Maria de Alvear, Carola Bauckholt, Branimir Krstić, David Sawer, Rickard Scheffer, Juan Maria Solare, Gerald Barry, and Chao-Ming Tung.
He died in Cologne on September 18, 2008 after a long illness, at the age of 76 (Nonnenmann 2008).