This song was written by Harold Arlen for the 1939 MGM classic THE WIZARD OF OZ. It is played here on the 1929 RCA theremin that once belonged to the late Hollywood thereminist, Dr. Samuel Hoffman. The theremin typically consists of a box with two metal antennas which create an electromagnetic field. The musician stands in front of the instrument and moves his hands in the proximity of the two antennas, which forms a capacitor between his hands and the antennas. http://y2u.be/K6KbEnGnymk