Antikhthon (Greek: Ἀντίχθων, which can be translated as Counter-Earth) is a ballet for orchestra composed by Iannis Xenakis in 1971.

I chose this latter form, but I gave it a mysterious, evocative title, in order to convey to the choreographer a semblance of an argument that would be more "concrete" than pure musical thoughts.The Pythagorean term anti-khthon means Counter-Earth.

This Greek term comes from the fifth or sixth century, when the Pythagoreans were the first people to assert that the earth is not the center of the universe.

Even though Xenakis felt deeply appealed by the idea of the Antikhthon, Balanchine was much more pragmatic about what he thought he could achieve, as he stated that it is limited to "the movements we can make with our limbs, our trunk and our head — and that's all.

Clarinetists have to play up to four different techniques, entitled "Zones" by Xenakis, which alter and enrich their sonorities.