INGEBORG EMGE, HARPE DE VERRE | Ingeborg Emge, Harpe de Verre, Glass harmonica, Benjamin Franklin, Marianne Davies, Mariane Kirchgessner, Mozart, glass harmonica, flute, oboe, alto, violoncello, Richard Strauss, Handharmonika, accordion, Mundharmonika, mouth organ

The glass harmonica was the ideal music instrument for the rococo, the eighteenth century's sensibilities, the "Werther" period. It was invented and built in 1762 in London by the American statesman and inventor Benjamin Franklin who was inspired by the "Glasspiele" ("musical glasses","verillon"). The musical glasses developed from Persian instruments, already several centuries old, made of glass or porcelain cups which were gently struck to produce a tone. The musical glasses proper were carefully selected glass goblets, tuned to specific pitch by partially filing with appropriate amounts of water, and played by rubbing the rims with moistened fingers.

Franklin's harmonica featured thirty or more pierced-bottom glass bowls of graduated sizes (self-tuned in chromatic sequence), concentrically mounted and each nestling into the next larger size. The bowls were mounted on a horizontal spindle which was rotated by a pedal-and-crank mechanism. The players still used their fingers on the exposed rims, but the closer juxtaposition of the bowls greatly eased the sounding of two or more tones simultaneously. The range of pitch of the earlier instruments was 2 ½ octaves; later instruments could reach nearly 4 octaves. The bowls corresponding to the black keys of a contemporary piano had guilt rims.

Franklin's glass harmonica became known in Europe thanks to Marianne Davies, a relative of Franklin. The instrument became particularly famous in Germany at the end of the rococo period, the "sensitive period". In Germany makers of musical instruments developed the glass harmonica into the keyboard harmonica, while in England the "musical glasses" continued to dominate and outlived the golden age (1765-1835) of the glass harmonica. The harmonica became the favourite instrument of the German courts of the time. The great virtuosi were found in Germany, among them the most famous was the blind artist Mariane Kirchgessner. Mozart, who had heard the glass harmonica in his youth, played by Marianne Davies, was so deeply impressed by Mariane Kirchgessner, at a concert given in Vienna in 1791 that, just six months before his death, he wrote one of most beautiful chamber music works for her, the Adagio and Rondo for glass harmonica, flute, oboe, alto and violoncello (K.617).

But although the glass harmonica had become such a favourite in a very short time, it died out very rapidly and disappeared completely from the European musical scene after 1835.

In the twentieth century Richard Strauss was the first to use the glass harmonica again in the opera "The woman without a shadow" (Vienna, 1919). But the lasting revival of glass instruments is due to Bruno Hoffmann, who devoted his whole life to promoting these instruments and music for them. His own instrument, the glass harp, is a set of 50 musical glasses, which are tuned to the notes of the chromatic scale and cover almost four octaves (D to C4). They are played in the original manner by rubbing the rims with moistened fingers. The instrument differs, however, from the originally spread row or loosely grouped assembly of glasses of the "musical glasses" in that those of the glass harp are mounted very close together on a framed wooden base. It thus eliminates variable water tuning and the more-or-less fixed rotational speed of Franklin's harmonica. The pitch depends on the size and the thickness of the glass. By analogy with the aeolian harp, Hoffmann chose the name glass harp for his instrument as he wanted to avoid any association with those instruments which in German are still called harmonica (Handharmonika - accordion, Mundharmonika - mouth organ) and bear no resemblance whatsoever to Franklin's glass harmonica.