The Ondes Martenot.

At the Usher Hall for a performance of Olivier Messiaen's amazing Turangalîla-Symphonie, first performed in 1949 under the baton of a young Leonard Bernstein.

To the right of the grand piano, front of stage, is the Ondes Martenot , an electronic musical instrument developed in 1928, a French cellist and inventor; similiar in sound to a theremin, this keyboard-based instrument uses changes in frequency oscillation produced in vacuum tubes to produce an eerie and futuristic tones that have scored science fiction and horror films since the Fifties.