The glass harmonica, also known as glass armonica, '"hydrocrystalophone" or simply armonica (derived from "armonia", the Italian word for harmony) is a type of musical instrument that uses a series of glass bowls or goblets graduated in size to produce musical tones by means of friction, making it both a crystallophone and a friction idiophone). Despite being played with wet fingers, the sound is produced by vibration of the solid glass, so that the glass harmonica is not a hydraulophone even if played completely submerged in water.
In Franklin's version, 37 bowls were mounted horizontally nested on an iron spindle. The whole spindle turned by means of a foot-operated treadle. The sound was produced by touching the rims of the bowls with moistened fingers. Rims were painted different colors according to the pitch of the note. As were dark blue, Bs purple, Cs red, Ds orange, Es yellow, Fs green, Gs blue, and accidentals white. With the Franklin design it is possible to play ten glasses simultaneously if desired, a technique that is very difficult if not impossible to execute using upright goblets. Franklin also advocated the use of a small amount of powdered chalk on the fingers which helped produce a clear tone in the same way rosin is applied to the bows of string instruments.
Here is a documentary about Glass Armonica
"Dance of the Sugar Plum Fairy" on the Glass Armonica
GLASS HARMONICA played by VERA MEYER





