First invented in 1761, thought by some to be the first instrument invented in America. Often demonstrated as a party trick. If you rub a wetted finger around the rim of a wine glass a very pure musical note is produced whose pitch cannot be altered except by adding water to the glass or grinding away glass from the bottom or the rim. During the eighteenth century it became popular at amateur musicians to play music on sets of singing glasses. The pastime might have remained an amateur amusement had it not been for Benjamin Franklin who spent most of the period from 1757 to 1766 in London and Paris as an agent for the American Colonies. Franklin heard a concert played on glasses by a virtuoso named Richard Puckridge and was struck with the ethereal beauty of the sound. Franklin never became interested in anything without putting the whole force of his inventive genius to work. He immediately conceived of a way to make a professional instrument. The first armonica built by Franklin exist today at the Franklin instite of Phiadelphia Pennsylvania.

He removed the stems and bottoms from the glasses, inserted corks in the holes in the bottoms and mounted them one after the other on a horizontal spindle. The spindle was rotated rapidly by means of a foot treadle (like an old fashioned sewing machine) and the player sat in front of the machine and touched moistened fingers to the edges of the rotating glasses. The first model was completed in 1761 and using the Italian word for "harmony", he called it the "Armonica"; this has later been changed to the "Glass Harmonica".

For the next half century the instrument became very popular and thousands were built and sold. Virtuoso players appeared, the most famous being Marianne Davies (1744-1792) and many composers including Mozart wrote for it. After about fifty years the instrument fell into decline, in fact, into disrepute. Its haunting sound suggested the supernatural and its association with the notorious hypnotist Dr. Franz Anton Mesmer did not help. There developed a widespread idea that it caused insanity and nervous disorders. There is a remote possibility that the constant contact of wet fingers on the glass leached out lead from the glass and caused lead poisoning. The instrument is making a modest revival and superb models are built today by a master glassblower, Gerhard Finkenheimer, in the United States. He uses pure quartz for the glasses not leaded glass.

Most of the musical instruments played today depend on the excitation of vibrations in only three different systems; the stretched string, the stretched membrane, and the column of air. Except for a very few specialized instruments, mostly of the percussive variety, all orchestral instruments are of this type. These three methods do not, however, exhaust the possibilities for producing sounds. The vibrations in solid and hollow bars are used in xylophones and gongs and the bell is a special form of vibration in a membrane. The actual vibrational modes which produce the sound are not at all well understood. Theory predicts that the higher harmonics of an individual glass should not be integral multiples of the fundamental frequency but measurements show that they are exact multiples. See Musical Scales. The glass medium is difficult to make observation on and so the underlying physics of the "Armonica" or "Glass Harmonica" remains as mysterious as its sound