0:08-0:38 Low male voices for Snoke. This is also reprised from The Force Awakens, but I'm not sure I can call it a “theme”.
0:38-0:49 Low, scratchy viola as we see Ren approach Snoke
0:49-1:12 Wannabe motive x2 by horn. Snoke: “When I found you...”
1:12-1:20 Imperial March. Snoke: “A new Vader. … I was mistaken.”
1:31-1:38 Brooding motive, bass clarinet
1:38-1:43 Power motive x1, muted trombone, e minor, as Ren takes off his mask.
1:43-2:06 incidental music leads to orchestral crescendo. Snoke: “You fail!”
2:06-2:22 more incidental music
2:22-2:30 low voices again
2:30-2:41 brooding, x2, cellos
2:41-2:57 brooding continues, wannabe superimposed. Snoke: “You're no Vader, just a child.”
2:57-3:17 Power motive, horn, x2 as Ren smashes his helmet
3:16-3:27 wannabe, horn
The Music of Star Wars
These posts will help focus and develop my analyses of John Williams' film scores.