Yeah, I also get the impression that is another version of the opening sequence of the movie. The clip seems to transition straight into the music that shows the First Order ships descending.
That upwards climbing string figure only appears on the album in the end credits and once in the body of the movie as an unreleased cue when Rey is with the storm trooper before she escapes. One can surmise from that youtube clip it initially was meant to have more of a presence in the movie. That brass figure that doesn't get used at all seems like a cousin of the Kylo Ren secondary theme that does get used. I think the explanation may be at least in part due to the way that Abrams re-edits the movie and gave Williams one piece of the movie at a time. There's a little bit of a hodgepodge of ideas related to Kylo Ren and the dark side as compared to if he were scoring less of a moving target I think.
That upwards climbing string figure only appears on the album in the end credits and once in the body of the movie as an unreleased cue when Rey is with the storm trooper before she escapes. One can surmise from that youtube clip it initially was meant to have more of a presence in the movie.
He also plays around with it in "The Ways of the Force." On the album, you can hear it from 1:08-1:20 of track 20. I'm referring to the climbing string figure here, not the brass figure in the above clip -- which does indeed sound like a riff on one of the themes for Kylo Ren.
This sort of multi-dimensionality isn't at all unusual for Williams. He often creates "collections" of motivic material for a single character that work together in complementary fashion -- sometimes in sequence, sometimes in counterpoint -- to paint a more layered musical portrait. Many of his greatest themes -- Indiana Jones, Superman, Jaws, etc. -- contain two or more distinct lines.
