But doesn't that imply an unusual awareness of the contents of those episodes? Unusual for a composer of that time, I mean. I got the impression, I guess primarily from the interviews in Bond's book, that the composers didn't spend a lot of time watching the shows they scored for. Of course they watched the episodes they scored; but in general they didn't have time to watch a season's worth of episodes of a show.
Duning's choice of those motifs to re-use, seems to display almost a fan's sense of the contents of those episodes, the relevance of those cues. Compare his interpolation of cues, to Fried & Steiner & Courage & Kaplan. All of them used Courage's Enterprise theme for flyby's, which was required. And then – what? Fried & Steiner & Courage quoted themselves, but only themselves so far as I can tell. Kaplan wrote two entirely distinct scores, with no material shared between them (I think).
Isn't Duning unique among the Star Trek composers, in quoting from the others? (Except for the Enterprise theme.)
Well, I'd say that Courage's romantic theme for the Romulan Commander in "The Enterprise Incident" is derived from Steiner's Romulan/Blackship Theme -- one sustained note, then three iterations of a descending pair with the third pair ending on the same note as the first, then a repetition of those three pairs, etc. I wouldn't be surprised if the track list for that episode includes a note saying "Based on a theme by Fred Steiner" for that, the same way that Steiner's Enterprise
theme is listed as "Based on a theme by Alexander Courage" since it's basically an inversion of the Courage fanfare.
As for Duning, yes, it's possible he watched the show; his "Return to Tomorrow" score was recorded a couple of months after "Mirror, Mirror" aired, and of course he didn't quote "Amok Time" until season 3. But it's also possible he just talked with his fellow composers about what they'd done, or with the producer or the music editor or whatever. Rather than being fannish, it could've simply been part of his process as a composer to compare notes in that way. It's unwise to read fan sentiment into professional work. I'm a Trek fan, of course, but when I write a Trek novel and incorporate ideas from other novels, I don't think of it as an expression of fandom, but as being thorough in my research -- or as saving myself work when I can find an existing idea I can use rather than having to come up with a new one.
For all we know, Duning could've simply been so pressed for time that it was easier to ask if there were existing themes that would suit his purposes.