The name glass harmonica refers today to any instrument played by rubbing glass or crystal goblets or bowls. The alternate instrument consisting of a set of glasses is generally known in English as musical glasses or the glass harp. When Benjamin Franklin invented his version of the instrument in 1761, he called it the armonica, based on the Italian word armonia. The unrelated free-reed wind instrument aeolina, today called the harmonica, was not invented until 1821, the word hydrodaktulopsychicharmonica is also recorded, composed of Greek roots to mean something like harmonica to produce music for the soul by fingers dipped in water. The Museum of Music in Paris displays a hydrodaktulopsychicharmonica, because its sounding portion is made of glass, the glass harmonica is a type of crystallophone. The phenomenon of rubbing a wet finger around the rim of a goblet to produce tones is documented back to Renaissance times, Galileo considered the phenomenon. The Irish musician Richard Pockrich is typically credited as the first to play an instrument composed of glass vessels by rubbing his fingers around the rims, beginning in the 1740s, he performed in London on a set of upright goblets filled with varying amounts of water. His career was cut short by a fire in his room, edward Delaval, a friend of Benjamin Franklin and a fellow of the Royal Society, extended the experiments of Pockrich, contriving a set of glasses better tuned and easier to play. During the same decade, Christoph Willibald Gluck also attracted attention playing an instrument in England. Benjamin Franklin invented a new arrangement of the glasses in 1761 after seeing water-filled wine glasses played by Edmund Delaval at Cambridge in England in May 1761. Franklin worked with London glassblower Charles James to build one, and it had its premiere in early 1762. In honour of your language, I have borrowed from it the name of this instrument. In Franklins treadle-operated version,37 bowls were mounted horizontally on an iron spindle, the whole spindle turned by means of a foot pedal. The sound was produced by touching the rims of the bowls with water-moistened fingers, rims were painted different colors according to the pitch of the note, A, B, C, D, E, F, G, and accidentals were marked in white. With the Franklin design, it is possible to play ten glasses simultaneously if desired, Franklin also advocated the use of a small amount of powdered chalk on the fingers, which under some acidic water conditions helped produce a clear tone. Some attempted improvements on the armonica included adding keyboards, placing pads between the bowls to reduce vibrations, and using violin bows. Another supposed improvement claimed in ill-informed post-period observations of non-playing instruments was to have the glasses rotate into a trough of water. However, William Zeitler put this idea to the test by rotating an armonica cup into a basin of water, with several dozen glasses, each a different diameter and thus rotating with a different depth, the result would be musical cacophony
Spinning glass disks (bowls) on a common shaft are arranged with the lower notes (larger disks) to the left and higher notes (smaller disks) to the right.
A glass harp, an ancestor of the glass armonica, being played in Rome. The rims of wine glasses filled with water are rubbed by the player's fingers to create the notes.
A modern glass armonica built using Benjamin Franklin's design
Dennis James plays the armonica at the Poncan Theatre in Ponca City, Oklahoma, on April 2, 2011.