I have the same chord that you mean then.
This is not a personal reflection of the chord and feeling produced from the chord. We are talking about a lot of films here that are the usual place where you may want music to emphasize tension. Was this chord ever used in a Hitchcock film for example? Maybe, but I doubt it was ever used in a scene that needed tension.
Music is usually composed for an audience and not just yourself. (You make more money this way.) It is important to bear in mind the effect something will have on an audience when they hear it and not just any theoretical notion. I'm still a bit puzzled with you saying that this chord has anything to do with tension.
I can see that this might be a music-theory type of tension but the most important thing is the effect that is given to the audience. I don't see what music-theory tension would have to do with that.
I am quite interested in this discussion as it ties in with my "much debated" notion that "too much music theory can be damaging to your compositional skills". Music is about sound and this is all the audience hears. I prefer to stay as close to that as I can and away from too much mechanics.
For something like the opening sequence of jaws I wouldn't be thinking chords at all. I think the good things that were used to create tension are:
1/ The slowly increasing volume of the music and instruments in the arrangement.
2/ The stabbing nature of the cello's
3/ The use of Cello's as opposed to say a flute.
4/ The music is very simple and direct
I think having the music in a sort of minor chord is important but I do think that use of a fully diminished chord here would have a serious effect on the box-office. (It fits! but it does make it sound too laid back and relaxed.)
I don't know how the main music to Psycho was written but I can imagine it being originated accidentally on piano. Similar to what you suggest but with two fingers close together. I can even imagine a child inspiring this as it sounds like something someone new to the piano would play if they were very young and just wanted to make a noise.
Wow! Now we're actually getting into my exact area of expertise- I'm glad you brought it up! I am a graduate student getting my Masters in music theory and film scoring- let's open up this can o' worms my friend! I am a pianist of classical music and I am a certified choir teacher as well. I have my Bachelor's of Music in Music Theory/ Classical Composition from a private university.
I have scored numerous films, chamber music (string quartets, trios, Songs for soprano/ tenor/ bass and piano, choral pieces, many piano pieces, etc.).
So, you believe that "too much music theory can be damaging to your compositional skills"? Well, if a little music theory is detrimental or "damaging" (to use your phraseology) to one's creativity, then that individual's creativity must be very *WEAK* to begin with, huh?
You mentioned Hitchcock films? You want to know a little about the composer that composed most of the music for his films, Bernard Herrmann? Educated at numerous universities for classical composition and favored the American composer of serious art concert music, Charles Ives- talk about fully diminished 7th chords... all this before he hit the scene of film scoring.
Film score composers: Max Steiner, Danny Elfman, John Williams, James Newton Howard, Elmer Bernstein, Nino Rota, Alan Silvestri, Howard Shore, Franz Waxman, Korngold, etc. ALL uses/ used music theory to write their film scores (and fully diminished chords)- guaranteed.
Of course Herrmann used fully diminished 7th chords (and YES, FOR TENSION) since he knew music theory from his university training.
Let's look at your list:
1/ The slowly increasing volume of the music and instruments in the arrangement. (calls for orchestration and it's called a "crescendo")
2/ The stabbing nature of the cello's (orchestration and called "Marcato")
3/ The use of Cello's as opposed to say a flute. (again, orchestration)
4/ The music is very simple and direct (Minimalism, a genre in classical music)
See, it's a language that you understand and can speak with other musicians so everyone is on the same page.
What's easier:
Asking someone for that hand-held cylindrical container filled with that clear liquid that helps with your thirst when you are hot? OR
A glass of water?
Semantics my friend and everyone gets the job done faster with less hassle.
I could go on and on, but I'll leave it at this-
music theory is what gave us the "popular progressions" that dominate the scene today, but just an extremely minimalistic version of it... Western tonality is based ON MUSIC THEORY. Jazz/ blues/ rag time/ Swing etc. took it and morphed the "traditional" common practices to the wonderful genres that they are today. This was taken further by the pop genres and now we have a miniature model of long-past music theory, but it is still what this ALL came from.
You don't have to know theory/ orchestration to write music, but it is a another tool that helps elaborate the music... you don't have to follow the rules of music theory, but the film score composers that you speak of do and I'd say that they are successful, don't you?
There's always a point in the producer's/ composer's life, if they are just guessing and not using at least a shred of theory, when they get stuck and need a little help to move on- this is where theory comes into play.
Take care.