Ennio Morricone made a few disgruntled comments about Carpenter's use of his score in The Thing. Mainly he was disappointed that Carpenter, after publicly stating he wanted a European sound to the music, simply used the music that sounded most like his own compositions. Further insult was added when Carpenter created several cues to mix in with Morricone's (even as a youngster I could clearly recognize Carpenter's work when I heard it in the film on its opening weekend).
Despite that, like the soundtrack for Dawn of the Dead, this soundtrack release contains all the music Morricone composed for the film and none of Carpenter's work. How well some of the tracks would have fit into the film, and where, is anybody's guess.
Morricone's score is, in the end, a superb effort that captures the tone and mood of the film beautifully and achieves the same level of excellence as Goldmsith's score for Alien and Williams's score for Jaws. An essential soundtrack in any library.01 Humanity (Part I)
08 Humanity (Part II)
11 Humanity (Movie Version)