Question: Who wrote the score for 2001 a space odyssey?
Disambiguated questions and answers: question: Who wrote the 2001: A Space Odyssey Score that was never used?
Who wrote the music that was used in 2001: A Space Odyssey?
answer: Alex North
Richard Strauss, Johann Strauss, and Aram Khachaturian
Natural Questions answer: Alex North (from the Wikipedia article "2001: A Space Odyssey (score)")