2001: A Space Odyssey (soundtrack) that shift slowly over time. 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 to being irritated by Kubrick's failure to obtain permission directly from him, he was offended that his music was used in a film soundtrack shared by composers Johann and Richard Strauss. The Richard and Johann Strauss pieces and György Ligeti's "Requiem" (the Kyrie section) act as recurring motifs in the film's storyline. Richard Strauss' "Also Sprach Zarathustra" is first heard in the opening title which juxtaposes the Sun, Earth, and Moon.
2001: A Space Odyssey (score) music would have been an improvement on the background music that Kubrick finally chose for the film." Conversely, in his notes for the Jerry Goldsmith recording, Kevin Mulhall argued that "there is no doubt that "2001" would have been better if Kubrick had used North's music. Even if one likes some of the choices Kubrick made for certain individual scenes, the eclectic group of classical composers employed by the director... resulted in a disturbing melange of sounds and styles overall." Film critic Roger Ebert noted that North's rejected score contains emotional cues to the viewer while the final music selections