What is the name of the term used for when the soundtrack composer, creates a song and the other songs are variations of the same song. For example, in the movie Inception, The Last of the Mohicans, Requiem For a Dream
This really is just called a variation and it's not limited to soundtracks, Wikipedia says:
In music, variation is a formal technique where material is repeated in an altered form.
A famous example of this are the Goldberg Variations.
A Leitmotif is by definition the leading theme of the overall piece, which would be the film in this case, so it may be the main character's theme tune, or the title theme, which is then the most likely candidate to be the tune which is varied throughout the rest of the film depending on the tone of the scene or emotional state of the character(s).
I've read about it. I also found the term
Leitmotiv. Now, I'm confused, hehe. pt.wikipedia.org/wiki/Leitmoti Aug 20, 2014 at 17:38
1@FelipeStoker I've added an edit to compare the two ideas Aug 20, 2014 at 17:43
2Fun fact: when I was 14 I saw The Dark Crystal and bought the soundtrack. Turns out several songs used the same melody, just with different "moods" and orchestrations. I remember a swelling full orchestra version, as well as a lively "galloping across the plains" version. There are probably other variations that I missed (or can't recall now that I'm 46!). Aug 20, 2014 at 18:28
Incepctionyou will understand better.