A guiding motif:
A Leitmotiv (German for “guiding motif”) is a theme that announces characters. Wagner was famous for using this idea, although he did not use the word “Leitmotiv”, but perhaps the most famous use of the Leitmotiv is by John Williams in Star Wars.
Here are just a few of the iconic themes that were all used and well-known by the time the first three films were completed. Using the idea of “famous old popular music”, which in this case is more like “slightly older popular music”, we now come to something a big different, since John Williams is still composing more music for Star Wars movies, some of which have not yet been released. How he writes these themes that we all know and can’t forget remains a mystery that I absolutely do not understand.
Darth Vader’s Theme
By the way, Darth Vader’s Theme uses only minor chords, moving from key to key.
Luke Skywalker’s Theme
Princess Leia’s Theme