Ivan, I have to say that your question is so intelligent you obviously know what you're doing already!
But it is a very interesting thread because it is about the most basic process. It's very hard to think about, in fact. Maybe most people do these things without being fully aware of what they're doing. I know I do. If I analyze what I've done - and I would be curious to know if other composers do something similar - any musical idea seems to start as a motif or melody that has a harmonic basis that isn't heard but felt. Also a feeling of some potential - as if you feel more can grow from it.
The writing is really "specifying" making what was abstract into something specific. I just sketch messy things that I myself often cannot read, and then try and do instrumentation and counterpoint. Often things are almost unavoidably for brass, or strings, or whatever because of the emotion of the music. In other words it is just a process of getting what you feel about the music somehow into the actual written-down score. However you do it! Though I am probably more chaotic in composing something than I should be. I sometimes feel as if I have a lot of pieces of a jigsaw puzzle and just keep shaking them and pushing them around until I have an order that seems to conform to their real shape. With film music it is easier in a way because the film demands certain things and rules out others. The form of the music comes from the film.
But it is a very interesting thread because it is about the most basic process. It's very hard to think about, in fact. Maybe most people do these things without being fully aware of what they're doing. I know I do. If I analyze what I've done - and I would be curious to know if other composers do something similar - any musical idea seems to start as a motif or melody that has a harmonic basis that isn't heard but felt. Also a feeling of some potential - as if you feel more can grow from it.
The writing is really "specifying" making what was abstract into something specific. I just sketch messy things that I myself often cannot read, and then try and do instrumentation and counterpoint. Often things are almost unavoidably for brass, or strings, or whatever because of the emotion of the music. In other words it is just a process of getting what you feel about the music somehow into the actual written-down score. However you do it! Though I am probably more chaotic in composing something than I should be. I sometimes feel as if I have a lot of pieces of a jigsaw puzzle and just keep shaking them and pushing them around until I have an order that seems to conform to their real shape. With film music it is easier in a way because the film demands certain things and rules out others. The form of the music comes from the film.