HARMONICA, a generic term applied to musical instru ments in which sound is produced by friction upon glass bells. The word is also used to designate instruments of percussion of the Glockenspiel type, made of steel and struck by hammers (Ger. Stahlharmonika).
The origin of the glass-harmonica tribe is to be found in the fashionable 18th century instrument known as musical glasses (Fr. verrillon), the principle of which was known already in the 17th century. The verrillon or Glassspiel consisted of 18 beer glasses arranged on a board covered with cloth, water being poured in whenever it was found necessary in order to alter the pitch, and the sound being produced by passing the moistened finger round the rims. (Or sometimes the sides of the glasses were struck instead by wooden sticks.) Gluck gave a concert at the "little theatre in the Haymarket" (London) in April 1746, at which he performed on musical glasses a concerto of his composi tion with full orchestral accompaniment.
When Benjamin Franklin. visited London, in 1757, he was so much struck by the possibilities of the glasses as musical instru ments that he set to work on a mechanical application of the prin ciple involved, the result being the glass harmonica finished in i 762. The instrument was for many years in great vogue. Mozart, Beethoven, Naumann and Hasse composed music for it, while it had its celebrated virtuosi, such as Marianne Davies and.Marianna Kirchgessner.
The curious vogue of the instrument, as sudden as it was ephemeral, produced emulation in a generation unsurpassed for zeal in the invention of musical instruments. The most notable of its offspring were Carl Leopold Rollig's improved harmonica with a keyboard in 1786, Chladni's euphon in 1791 and clavicylinder in 1799, Ruffelsen's melodicon in i 800 and 1803, Franz Leppich's panmelodicon in 181 o. Most of these have long since completely disappeared. The name, harmonica, is applied also to the aeolina, a small mouth organ, invented by Sir Charles Wheatstone in 1829. A few free reeds, each supplied with wind separately from the mouth of the player, are fastened in a small metal box. The tune is made by moving the instrument to and fro across the mouth, simple tunes being the result.
For the steel harmonica see GLOCKE}eSPIEL.