This is an accelerated assembly video for the $29.95 Gakken Mini-Theremin kit, via Make Magazine.
The theremin, invented in 1919 by Russian scientist Leon Theremin, is one of the world’s earliest fully electronic instruments, and is also unique in that it was the first musical instrument designed to be played without being touched. The eerie, other-wordly tones as heard in the films mentioned above are created by the proximity of the player’s hands to the metal antennas, with the resulting radio frequency interference being transformed into musical tones. Instructions are in Japanese but features highly detailed assembly pictures, sorry no English translation at this time. Easy to build and play!