Film Music and Opera

I have been trying to research the history of film music and where the idea of music as an emotional stimulus as opposed to the covering of silence came from.

The big tie here sees classical music and more predominately, opera showing clear narrative driven music to enhance and engage the story at a heightened level of characterization. "Overtones and Undertones" a book by Royal. S Brown quickly recaps on the relationship between Wagnerian opera and it's common traits found in todays film scores.

Wagners compositions are widely recognised for their use of characters themes and leitmotifs that are now a staple of association with characters and themes in film today. Wagner was able to take a character such as Gutrune in his opera "Der Ring des Nibelungen" and use a theme to associate that character with the music.
These themes that represented not only characters but emotive feelings and conflicting views within the story are more important for their immediate emotional impact and in their relationship to the dramatic structure of the opera than they are to the underlying musical structure (Brown,R. 1994).

Wagner didn't invent the idea of putting music to film but he produced compositions for story that didn't just enhance the story but embodied the story, captured the characters within the story and developed their feelings into music for the audience to understand and feel that they knew who the characters were and how they felt.