2001: A Space Odyssey (soundtrack) mankind's eventual replacement by overmen ("Übermensch") in Nietzsche's work "Thus Spoke Zarathustra". "Gayane's Adagio" from Aram Khachaturian's "Gayane" ballet suite is heard during the sections that introduce Bowman and Poole aboard the "Discovery", conveying a somewhat lonely and mournful quality. In addition to the majestic yet fairly traditional compositions by the two Strausses and Khachaturian, Kubrick used four highly modernistic compositions by György Ligeti that employ micropolyphony, the use of sustained dissonant chords that shift slowly. This technique was pioneered in "Atmosphères", the only Ligeti piece heard in its entirety in the film. Ligeti admired Kubrick's film but, in addition
Interpretations of 2001: A Space Odyssey machines". Kubrick was also confronted with the fact that, during the production of the film, the US and USSR had agreed not to put any nuclear weapons into outer space by signing the Outer Space Treaty. Alexander Walker in a book he wrote with Kubrick's assistance and authorisation, states that Kubrick eventually decided that as nuclear weapons the bombs had "no place at all in the film's thematic development", now being an "orbiting red herring" which would "merely have raised irrelevant questions to suggest this as a reality of the twenty-first century". In the Canadian TV documentary "2001 and Beyond",