Karlheinz Stockhausen, one of the world's most influential 20th century composers and renowned for his pioneering work in electronic music, has died aged 79.
German media quoted the Stockhausen Foundation and Stockhausen's former wife Mary Bauermeister as saying the musician died on Wednesday after a short illness at his home near Cologne in western Germany.
Best known for experiments with electronic music in the 1960s and 70s, Stockhausen, who composed more than 300 individual works, also had a significant impact on avant-garde and classical music.
The Beatles paid tribute to Stockhausen by putting him along with other icons on the cover of "Sergeant Pepper's Lonely Hearts Club Band". Miles Davis and more recently Bjork have cited him as a musical influence.
"Any sound can become music if it is related to other sounds ... every sound is precious and can become beautiful if I put it at the right place, at the right moment," he once said in an interview.
He also said he loved silence.
Early in his career, Stockhausen dabbled in "musique concrete", recording everyday sounds, distorting them electronically and joining them together to form a composition.
From works for solo instruments to large-scale events mixing opera, dance and mime, Stockhausen said he aimed to awaken "a completely new consciousness" in listener and performer.
Born on August 22, 1928, in Burg Modrath, a village near Cologne, Stockhausen said he was badly scarred by his experience of World War Two, in which he was a stretcher-bearer.
His father was a schoolmaster who died serving in the German army.
In his 20s Stockhausen flirted with jazz, playing the piano to support himself through the Cologne Music School, where he gained a teaching certificate in 1951.
He had already begun to compose, and moved to Paris to study under composers Darius Milhaud and Olivier Messiaen.
His experiments with electronic music took off at the newly-founded West German Radio Studio for New Music in Cologne, where he worked from 1953, later becoming its artistic director.
He found his own ways of assembling sounds to form a composition, developing the ideas of an earlier generation of European composers, like Schoenberg, who composed around a series of sounds instead of developing and repeating a theme.
In early works Stockhausen explored not melody, but the quality and relation of one sound to another. "Gesang der Juenglinge" (1956), staged for five sets of loudspeakers, has been described as a "sonic ballet", where the position of each loudspeaker is crucial for the acoustic images produced.
In a mix of solo and ensemble music, electronic and concrete techniques together with mime, a key work "Licht" was premiered at Milan's La Scala opera house in 1981, marking Stockhausen's increasing stature in conventional classical circles.
Stockhausen came under fire for comments about the September 11th attacks on the United States. He was quoted as saying the strikes were "the greatest work of art imaginable".
"Minds achieving something in an act that we couldn't even dream of in music, people rehearsing like mad for 10 years, preparing fanatically for a concert and then dying, just imagine what happened there," he was quoted as saying.
He later said he meant that only the devil could have orchestrated the attacks.
The composer was married twice and had six children and will be buried in a forest cemetery in the town of Kuerten, near Cologne, according to German media quoting the Stockhausen Foundation.