In 1928, the German composer Robert Beyer published a paper about "Raummusik" (spatial music), which is an entirely different sense of the term. Karlheinz Stockhausen, who became a colleague of Beyer in Cologne in 1953, used the expression "space music" in this sense when describing his early development as a composer: "The first revolution occurred from 1952/53 as musique concrète, electronic tape music, and space music, entailing composition with transformers, generators, modulators, magnetophones, etc., the integration of all concrete and abstract (synthetic) possibilities within sound (also all noises) and the controlled projection of sound in space." In the sense meant here, he stated in 1967, "Several have commented that my electronic music sounds 'like on a different star,' or 'like in outer space.' Many have said that when hearing this music, they have sensations as if flying at an infinitely high speed, and then again, as if immobile in an immense space." A number of Stockhausen's later compositions (not all of them electronic music) take outer space as their theme: "Sternklang" (Star Sound, 1971), "Ylem" (1972), "Sirius" (1975–77), several components of the opera-cycle "Licht" ("Weltraum" (Outer Space, 1991–92/1994), ' (1997), "Komet" (Comet, 1994/1999), ' (Lights—Waters, 1998–99)), and the so-called "Urantia" subcycle of "Klang" (Sound, 2006–2007), extending from its thirteenth "hour", ' to its twenty-first "hour" '.