How did the theremin expand the sounds available to musicians?

The theremin expanded the sonic palette available to musicians by serving as a novel electronic instrument designed to produce timbres not found in traditional acoustic instruments. Invented in 1920, it operates as a beat-frequency audio oscillator that allows performers to control pitch and amplitude through hand movements near its antennas, rather than through physical contact with a keyboard or strings.12

This unique interface enables a skilled player to produce a wide range of expressive effects, including continuous glissandi, flutters, and various scales. Furthermore, the instrument offers a range of six octaves, and its harmonic content can be filtered to create diverse tone colours. By providing these capabilities, the theremin moved beyond the limitations of instruments intended to simulate traditional sounds, instead offering avant-garde composers and performers a new medium for creative expression. Its distinct, otherworldly sound has since been utilized in various musical genres, including rock and science fiction film scores.12