It is the beginning of the second half of the cycle, and all of the music after the thirteenth hour is electroacoustic, employing partial mixdowns of Cosmic Pulses as the tape accompaniment.
[9]During his lectures surrounding the German premiere, Stockhausen said that he had "not made up his mind concerning it" yet,[10] and he admitted that the piece might be regarded as "not music, just sound" and it might be better to "just take it as a natural phenomena [sic] and not think of composition".
[2] Joachim Haas and Gregorio Karman from the Experimental Studio for Acoustic Art of Südwestrundfunk (SWR, "Southwest Broadcasting") in Freiburg, which had been founded on 1 September 1971 as the Experimentalstudio der Heinrich-Strobel-Stiftung des SWF,[12] created the OKTEG, a special piece of equipment to allow Stockhausen to realize the spatialization manually.
Reviewing the course concerts in MIT's Computer Music Journal, Nick Collins called the source timbre "a rather cheap electric piano sound",[10] and reported that those in the audience "who had heard more recent electroacoustic music were slightly perturbed by the bad timbre at the start for the source sound".
[10] However, Collins observed that this was "quickly subsumed into the granular storm as the layers gather and tempi increase", concluding that, notwithstanding audience consensus that "the overload last[ed] too long in the middle … It might cautiously be claimed that Mr. Stockhausen achieved a controversial success, and created a work that has reinvigorated his electronic music".
Collins shared his shorthand notes, which he scribbled in the dark during the performance: violent spasms of space, serial recurrences, a Copernican asylum, over-literal crashes, rushing more and more beyond sense, like being inside Stockhausen's mind as he composes, a battle of enraged keyboardists in a tempo war, granular roars, bass pedals and clatters, gurgling granules accelerate, pushing the boundary of information, tapes spooling mercilessly, a labyrinth of tone pulses, a multiplicity of collisions in an organ factory, even poor synthesis can't ruin this controlled chaos, wider and wider dynamics and layering, building to the synchronies of planets, raging layers, raging presets in a keyboard shop war, a fight at an audio convention.
[10]Describing the UK premiere at the BBC Proms, Nick Emberley felt that "the Albert Hall sounded like a mighty beast woken from slumber".
"[17] In The Sunday Times, Paul Driver described Klang as characteristically "portentous" and the organization around the 24 hours of the day as unexpectedly "obvious".
He praised Cosmic Pulses, "If one tried to imagine a kind of background roar to the universe, this is surely how it would be: incessant and implacable, like magnified wave crashes, cheerfully apocalyptic.
"[18] John Allison wrote that Cosmic Pulses "was thrilling: as rumbling and splintering noises ricocheted around the Albert Hall, it felt as if Stockhausen had dropped a microphone into deepest space.
"[20] Ivan Hewett described the piece as "a vast, half-hour hurricane of sound" that "to my earthly ears it seemed oppressively unvaried, despite fascinating moments".
[21] Andrew Clements wrote admiringly "[Cosmic Pulses] is an extraordinarily powerful creation by any standards, both poetically beautiful and utterly terrifying.