Karlheinz Stockhausen worked briefly in Schaeffer's studio in 1952, and afterward for many years at the WDR Cologne's Studio for Electronic Music.
In Cologne, what would become the most famous electronic music studio in the world was officially opened at the radio studios of the NWDR in 1953, though it had been in the planning stages as early as 1950 and early compositions were made and broadcast in 1951. The brain child of Werner Meyer-Eppler, Robert Beyer, and Herbert Eimert (who became its first director), the studio was soon joined by Karlheinz Stockhausen and Gottfried Michael Koenig. In his 1949 thesis Elektronische Klangerzeugung: Elektronische Musik und Synthetische Sprache, Meyer-Eppler conceived the idea to synthesize music entirely from electronically produced signals; in this way,elektronische Musik was sharply differentiated from French musique concrète, which used sounds recorded from acoustical sources.
"With Stockhausen and Mauricio Kagel in residence, it became a year-round hive of charismatic avante-gardism [sic]"on two occasions combining electronically generated sounds with relatively conventional orchestras—in Mixtur (1964) andHymnen, dritte Region mit Orchester (1967). Stockhausen stated that his listeners had told him his electronic music gave them an experience of "outer space," sensations of flying, or being in a "fantastic dream world". More recently, Stockhausen turned to producing electronic music in his own studio in Kürten, his last work in the medium being Cosmic Pulses (2007).