Ondes Martenot

The ondes Martenot, an electronic instrument invented by the French musician Maurice Martenot, produces single sounds by means of a keyboard that controls the frequencies from an oscillator. It has a wide range and offers the possibility of glissando. It became popular among French composers, including Milhaud, Honegger, Koechlin, Schmitt, Ibert, Jolivet, Messiaen and Boulez. Varèse also wrote for it, as he did for the less versatile electronic instrument, the theremin.