Modern Mechanix » Flashlight Beams Make Music On Photo-Electric Marimba

Also mentioned on Future Music:

The marimbalite makes any evening out something special. As the tuxedo-clad artiste waves his torches at the instrument in time to a Latin beat the light energises the photoelectric cells, which trip relays that actuate little hammers that hit the xylophone. Personally, I'd stick with the little hammers and eliminate the middle man.

The real fun is when a waiter accidentally spills a tray of drinks on the thing and you can watch a whole bank of electronics short out.

Sparks everywhere. Magic.

Flashlight Beams Make Music On Photo-Electric Marimba

MODERN electronic engineers duplicate the music of a primitive marimba band with light beams, photo-electric cells and radio tubes. Dr. Phillips Thomas of the Westinghouse Research laboratory recently demonstrated a “light music” instrument which played by waving flashlights held in each hand.

Dozens of photo-cells and radio tubes are lined up side by side atop the new musical device. For each musical note there is an oscillating circuit which produces electrical vibrations when light is directed on that circuits photo-cell. Reproducers convert the electrical vibrations into sound which is directed into the marimba pipes.