The Theremin

The Theremin was named after its inventor, Leon Theremin. It's an electronic instrument giving off a weird sound. Because of this it's often used for psychological scenes or sci-fi films.
    Miklos Rozsa introduced the instrument into Hollywood scoring with his landmark scores for The Lost Weekend (about an alcoholic with the DTs, or "delerium tremens") and Alfred Hitchcock's Spellbound, both 1945 (Rozsa won his Oscar for the Spellbound score, though he was nominated for both). T
    hereafter the Theremin became a cliche. It was used successfully, however, in two important sci-fi scores of the 1950s: Dimitri Tiomkin's score for The Thing (from Another World and Bernard Herrmann's great score for The Day the Earth Stood Still.
    Rozsa used it as underscore for the scenes in Spellbound when the hero (Gregory Peck) is haunted by memories of his childhood trauma (he accidentally killed his younger brother). You can see how the Theremin is played here. Or if your cookies are emptied you can use the console below: