[Nick Zwar]

You don’t need patterns and frequency to establish what film music is, because that is actually easily established. It is music written specifically for a film. I think we agree on that?

So you can of course look for patterns and look for commonalities, for styles and tropes and whatever, all of this is fair and square, but you extract patterns and statistics from a mass of work. You do not then try to reverse it by trying to apply the pattern and statistics to individual works.
Scores like ONCE UPON A TIME IN THE WEST are no more “exceptions” to the rule than Beethoven’s 9th Symphony is an “exception” to the symphony. Yes, they are both “exceptional”, but in the sense that they are particularly good, not in that they are particularly “unfit to represent the art”.

I think film music has special characteristics as MUSIC that sets it apart from other types of music

Name one.