The Empire, The Rebellion, The Force; They've all got their visual cues and they've all got their own sound in the Star Wars SciFi-Fantasy universe.
We recognize The Imperial March and Luke's Theme as cultural icons at this point, because that is what a strong theme, or leitmotif, does. It brings to mind the image and the feeling of the character or situation that it describes.
But times are a-changing. And now we have "BRAAAM!"... Wait, what?