The Theremin is often described as having a vocal-like quality, ranging from a soprano voice to a cello. This is due to its continuous pitch-shifting capability, which mimics the natural glissando of the human voice. Because it lacks tactile feedback, the player must rely entirely on their ears, much like a singer or a violinist. Clara Rockmore, the most famous Theremin virtuoso, developed a 'fingering' technique where she used small hand movements to precisely 'snap' to notes, allowing her to play rapid, complex classical pieces like Saint-Saëns' 'The Swan.' Interestingly, the Theremin operates on the principle of 'heterodyning,' where two high-frequency oscillators interact to create an audible frequency. Despite its science-fiction reputation, Leon Theremin originally envisioned it as a tool for high-brow classical music.