2001: A Space Odyssey (soundtrack) used is Ligeti's "Lux Aeterna" and an electronically altered form of his "Aventures", the last of which was so used without Ligeti's permission and is not listed in the film's credits. Since the film, "Also sprach Zarathustra" has been used in many other contexts. It was used by the BBC and by CTV in Canada as the introductory theme music for their television coverage of the Apollo space missions, as well as stage entrance music for multiple acts including Elvis Presley late in his career. Jazz and rock variants of the theme have also been composed, the most well known
2001: A Space Odyssey (film) its initial release. "2001: A Space Odyssey" is now considered one of the major artistic works of the 20th century, with many critics and filmmakers considering it Kubrick's masterpiece. Director Martin Scorsese has listed it as one of his favourite films of all time. In the 1980s, critic David Denby compared Kubrick to the monolith from "2001: A Space Odyssey", calling him "a force of supernatural intelligence, appearing at great intervals amid high-pitched shrieks, who gives the world a violent kick up the next rung of the evolutionary ladder". Poet and critic Dan Schneider wrote that "2001: A Space Odyssey"