Karlheinz Stockhausen

One of the most influential and unique composers of the 20th century, Stockhausen not only was a large figure in the classical world, but also in the newly emerging popular electronic scene in Germany. Interested in acoustics and how the shape of the space or perspective in space could affect sound and experience of a performance, he explored serialism and chance music in addition to electronica, where he focused on the most basic aspect of music, sine waves, and their manipulation to create music. Electronic Study I (1953) was the first piece ever composed with sine-wave sounds. He was involved more directly in the electronic music scene when he served as artistic director for a number of years for the electronic music studio at West German Broadcasting (Westdeutscher Rundfunk), where he had the opportunity to choose the type of electronic music recorded and broadcast and oversee its development. His interest in "the integration of all concrete and abstract (synthetic) sound possibilities (also all noises), and the controlled projection of sound in space" (Stockhausen 1989b, 127, as quoted in the Wikipedia article), as a classical composer, no less, was greatly influential for popular bands in terms of musical choice and in terms of more widespread acceptance of electronic music. He played around with tones and waves and encouraged experimentation. Stockhausen's music is more intellectual, I think, than later bands which incorporated the Western rhythms and sounds of rock and roll, but both share an alien, other-worldly quality that conveys vast amounts of empty space stretching to infinity.

http://www.furious.com/perfect/ohm/wdr.html
en.wikipedia.org/wiki/Karlheinz_Stockhausen
Stockhausen, Karlheinz. 1989b. Towards a Cosmic Music. Texts selected and translated by Tim Nevill. Shaftsbury: Element Books. ISBN 1852300841