I can’t believe that in all my years of viewing the film hundreds of times, I never picked up on this . Turns out Vader had a theme before the Imperial March that was a lot more subdued in the original film . The video they link to near the bottom of the page really makes one aware of it . Now I will never be able to not notice it on future viewings !..http://episodenothing.blogspot.com/2016/09/the-music-of-star-wars-that-we-never_16.html
By the winged devils of Onderon! I KNOW that piece of music, could hum it… but my brain never thought of it as a THEME/MOTIF in that way. It’s overshadowed in my brain box by the more dynamic Imperial March, which is strengthened by being in multiple films.
It’s a very low-key motif. More fitted to represent a bureaucracy than a regime of terror. Hardly surprising that John Williams thought better of it in subsequent films.
Yeah, but the Empire IS more bureaucratic. Grand Moff has staff meetings where people are allowed to argue. Until SW starts they’ve been used to answering somewhat to the Senate. Subordinates talk back to Vader and he listens.
By ESB things have changed. Vader is driven, and has the big boss chair unquestioned. The reign of terror has really begun. So the theme switch really fits the films.