In Part Six, composer Leonard Rosenman discusses Star Trek IV: The Voyage Home, where Kirk & Co. save the whales to save the world:
The greatest challenge that it posed was that you're dealing not with something new but with 20 years of habit with Sandy Courage's theme. The idea of trying to create, as Jerry [Goldsmith] did, and I think even Jamie [Horner] tried to do it, a new Star Trek theme is shoveling sand against the waves. My original idea, and as a matter of fact, even the script, called for Sandy Courage's theme at the beginning. I thought, "Well, if I have to do it, I'll make a fantastic arrangement of it, the kind they've never heard before." I took it a bit slower and very sweeping, and then for the rest of the film I had my own music...By the way, Nimoy later tried to get Rosenman rehired for Star Trek VI: The Undiscovered Country, but director Nicholas Meyer wanted to make his own choice, and the budget likely called for a newer/younger/cheaper composer. Meyer made a good choice in Cliff Eidelman; I'm really fond of his Star Trek VI score. I wish Eidelman had had a bigger career following it.
When we mated the music to the film, [director] Leonard [Nimoy] liked my arrangement of Sandy's theme for the main title, but felt it didn't show the film was fun at all.
We were in [Nimoy's] office at the time, and he took a tape of the end credit and put it at the film's beginning. "That's what we need!" he said. "Let's throw the Courage theme out and redo the main title." We just used the opening fanfare of Sandy's theme. Leonard wanted that sense of adventure and fun, something like a fast chase, which it was.