I did a course in undergrad on Music of the Cinema and we looked a bit at Star Wars. Prof was an opera expert so we overdosed on opera (5 versions of Carmen...)
Prof had a couple of things. First, commonly known that there is hardly ever an absence of any music in Star Wars and this was done to cover up the often horrendous dialogue.
Second, lots of directly parallels between Star Wars and Wagner's Ring Cycle.
Also, cool jackets:
Yeah, it's good stuff. I seem to recall from a "making of A New Hope" documentary that the only thing that was exceeding expectations and on schedule during development was the amazing soundtrack. The Star Wars movies are garbage without their soundtrack.
While John Williams' illustrious career speaks for itself, I think his music notably transformed a number of movies moreso than is typical - e.g. Jaws, Star Wars, Jurassic Park, Indiana Jones, and Close Encounters. What Williams did with just two notes in the Jaws theme to build dramatic, visceral tension is impressive.
And the opening theme to Lost in Space, I think.
I went to see a film at the AFI once selected and presented by Leonard Slatkin when he was leading the NSO. It was somewhat in the mold of Carrie (young male paranormally gifted person rather than female) although the plot as far as I remember it resembled Firestarter more among King works and it was... not very good. Had Kirk Douglas in it being Kirk Douglas but elevating the material was apparently beyond him. But not in Slatkin's opinion, at least not entirely, beyond Williams' score.