The theremin is an electronic instrument that is played by moving one or both hands in the proximity of two antennas. It is unique in that it does not require any physical contact with the instrument to produce sound. The theremin is often used in film and television scores to create eerie or otherworldly sounds.
2. Ondes Martenot
The ondes Martenot is another electronic instrument that was invented in the early 20th century. It is played by moving a metal ring around a metal rod. The ondes Martenot produces a ethereal sound that is similar to the theremin.
3. Hurdy-gurdy
The hurdy-gurdy is a stringed instrument that is played by turning a crank. It produces a continuous drone sound, and the melody is played by pressing keys on the fingerboard. The hurdy-gurdy is often used in folk and traditional music.