The Ondes Martenot is an early electronic musical instrument invented in 1928 by French musician Maurice Martenot. It produces sound through the oscillation of electrical currents, allowing for a wide range of pitches and timbres. The instrument is played using a keyboard and a ribbon controller, enabling performers to create smooth glissandos and expressive tones. The Ondes Martenot has been used in various musical genres, including classical, film scores, and contemporary music. Its unique sound has been featured by composers like Edgard Varèse and Olivier Messiaen, making it a distinctive addition to the world of electronic music.