Given that my 'Film Music Chord Change' proved to be quite popular, I decided to write another post in a similar vein. I may even get the chance to expand this into a vague series of sorts.
This post is about certain kinds of techniques, harmonies or whatever that have been used in specific scenes and as a result they have become an important part of the 'language' of film music. Very often film music has to fall back upon existing music to meet audience expectations and therefore I feel it is important to know what kinds of musical devices have been used.
So, here I'll begin with a specific technique that John Williams used a fair few times in Star Wars and Indiana Jones. I've nicknamed it 'polytonal chromatic mediants' but this label is neither accurate (not all chords are mediants) nor comprehensive (as there are plenty of polytonal chromatic mediant ideas that are completely different from this). Still, it works for me anyway...
The best example I can use for this technique is from the opening scene of Star Wars: A New Hope. This music is clearly heavily derived from Holst's Mars and there is this pounding ostinato in the background while the 'Rebel Fanfare' plays across it. Similar examples are played throughout this movie at varying levels of intensity. Although I've found this technique in other films, a recent example I heard was in parts of the opening space battle from Star Trek: First Contact.
Right then, let's build an example of this. For me, there are two ways to start a piece like this. Either create the melody first or create the rhythm first.
The melody should be fairly diatonic and quite simple. Perhaps only 5 different notes. For the real JW effect ensure that there is at least one semitone movement in there.
For creating a rhythmic ostinato, consider using the usual suspects: double basses, cellos, timpanis, gran cassa, trombones, tubas, bassoons, etc. Although the rhythm can be quite complex, it is best to simply pound away on one note. Don't worry if you don't know quite which note yet as we can decide that later.
So, with the melody and rhythm here, we can move into the final aspect, harmonising that melody line. The general approach is to use basic triads and make frequent parallel moves (i.e. keeping the voicing the same). This is particularly true in semitone movements. With the other movements, this is a good chance to use chromatic mediant or tritone ideas.
Once the harmonised section has been created we can work on an appropriate bass note. We want something slightly out of key to give a floating quality to this harmonised melody and keep it sounding tense. This is what gives the polytonal nature to the technique.
For examples in my own works, the best place is at the end of Droid Arena. There I used a variation on this idea where I specifically used slightly harsher harmonies. It basically is a disguised version of the Rebel Fanfare again.
Also, in Night Escape near the intro, a similar idea occurs again, this time more in the style of Jerry Goldsmith. The difference here is the ever changing time signature and the chromatic mediant moves are emphasised rather than a specific diatonic melody.
Ok, well something to think about anyway and hopefully I'll get some great comments back from the other posters here!