Torn Curtain had a great score by Herrmann that was abandoned by Hitchcock and replaced with a ordinary one that the studio heads wanted. At the same time Hitchcock fired Herrmann - right on the soundstage where he had assembled that orchestra for the first rehearsal. That was the end of their association forever. It was because Hitchcock had been ordered by the studio heads to have a light marketable music score for the film and he obeyed them. Herrmann did not, and never compromised on any artistic matter even slightly. He was right of course, since the film is a very dark espionage Cold War film - why would someone want lighter music for that?
The Herrmann score to Torn Curtain has been recorded several times since including a very good one conducted by Elmer Bernstein. It is for a very unusual orchestra of 12 flutes, 16 horns, 9 trombones, 2 tubas, percussion, cellos and basses only. He wanted the flutes to sound frightening rather than beautiful and they do have a creepy, almost insane quality in the fascinating music he did for the somewhat less successful film. The film itself isn't as bad as some people seem to think - a lesser Hitchcock film is a still a very good one compared to others! It has the amazing "Killing of Gromek" scene about which Hitchcock stated "I wanted to show how difficult it can be to kill a man." However it was terrible that their collaboration ended with that studio-caused fiasco.