How Douglas Trumbull's 1972 low-budget, bleeding heart science fiction classic yielded not just the basic look of, but the humanity of R2-D2 and robots everywhere.
The Imperial Attack / Blockade Runner track from the Star Wars score has a certain resemblance to the Crucifixion track from Franz Waxman's 1935 Bride of Frankenstein score. A track which was reused, as it happens, as the intro music for the Flash Gordon serial (and more on that later).