Composed in the summer of 1951, this was the composer's first soundtrack after he moved to Hollywood. Herrmann chose a most unusual instrumentation for director Robert Wise's picture, including electric violin, electric bass, two theremins, test oscillators, vibraphone, four pianos, four harps, and approximately 30 brass instruments. Unusual overdubbing and tape-reversal techniques were also used. In Edmund North's script, based on a 1940 story by Harry Bates, a humanoid alien named Klaatu, bearing a message of peaceful coexistence with other planets (the alternative is Earth's destruction), lands his flying saucer in the middle of Washington, D.C., accompanied by his giant robot Gort. "Prelude: Outer Space" features patterned, steadily arpeggiated harps and pianos, through which Richard Strauss-like high brass and eerie theremin melodies sail. In "Radar," multiple pianos are backed by electric bass pizzicati and sustained vibraphone chords. This music underlines the worldwide transmission of news about the saucer's landing. "Gort" accompanies the robot's emergence from the ship to defend Klaatu, who has been shot by nervous, trigger-happy soldiers. The music is made from piano, percussion, brass, and theremins. "The Robot" is a similar piece from later in the movie (when a kindly widow returns the apparently dead spaceman to his ship). "Space Control" is light and mysterious, full of bells and pianos, with a melody on electric guitar. "Terror" is a general cue for theremins used throughout the film, including the day when Klaatu demonstrates his power to stop all the world's engines. "Farewell and Finale" underscores Klaatu's final message, repeating the initial opening music and ending in a sustained major chord with odd wailing from the theremins. A unique score, ahead of its time, prophetic of many devices and sounds to be used for decades to follow, and still a model of impressive emotional effect achieved by musically economical means.