Have you ever tried to make a wine glass sing? Just wet your finger, move it along the rim of the glass, and within a few seconds you will hear a very special sound, pure and shining like the glass itself.
Perhaps your dinner partner's glass is still filled with wine. Let him rub it, and there will be another tone. This can be tuned by drinking or adding some drops of wine (or water), until the two glasses sing together in a simple chord... And there you are, producing the intriguing sound of the "musical glasses".
But glass music is not limited to this
kind of amusement at a dinner party. As far back as the
Middle Ages, glasses were used for musical purposes. In
China and Persia, crystal bowls and bells were tuned and struck
with soft drumsticks. In 1492, a set of tuned glasses (used
in a “Pythagorean experiment”) was described in
Gaffurio’s “Theorica musicae”, and Bohemian
minstrels used the glass “verrillon” to enchant their
audiences.
Irishman Richard Pockrich was the first to play classical music on the glasses. His various-sized “musical glasses” were tuned with water, and he played them by rubbing their rims with his wet fingers. The fascinating sound of his singing glasses soon became popular throughout Britain. In 1746, Christoph Willibald Gluck played a concert on “26 musical glasses, tuned with spring water” at the London Haymarket Theatre, having enthusiastically promised to perform “everything that can be done on a violin, or a harpsichord”. And so the art of glass music spread.
The most important development in
glass music came when, in 1761, young Benjamin
Franklin heard a
recital by glass virtuoso Edmund Delaval. Franklin was so
impressed by the instrument that he looked for a way to improve
it. As he wrote to his friend, Giovanni Battista Beccaria,
in Italy: 
"Being charmed by the sweetness of its tones, and the music he produced from it, I wished only to see the glasses disposed in a more convenient form, and brought together in a narrower compass, so as to admit a greater number of tones, and all within reach of hand to a person sitting before the instrument (...)"
Franklin chose 24 glass bowls, had them tuned by grinding, and mounted them concentrically on a horizontal rod. Driven by a treadle (very much like an old-fashioned sewing machine), the glasses spun around, and the player had only to touch the glasses with wet fingers.
Franklin called the instrument the “armonica”, “in honor of your (i.e. the Italian) musical language”.
Soo after the invention, Marianne Davies, a relative of Franklin’s, gave the first performances on the armonica in Europe. Her concerts in London, Bristol, and Dublin were followed by a tour of the continent, where she and her instrument soon became popular. Like Franklin, her audiences were charmed by its sound, as were the composers of the “Werther” era.
The first music genuinely written for the armonica was a cantata by Johann Adolf Hasse, which was performed at the wedding of the Austrian Duchess Maria Amalia. Its enthusiastic reception established the armonica in Austria and Germany, where it was particularly successful – and where its name acquired an additional “h”, as it was called the “Harmonika” in German.
Once German glassmakers had learned to build the delicate instrument, it was used in many German courts, where the local musicians—e.g. Johann Gottlieb Naumann, Johann Abraham Peter Schulz, Johann Friedrich Reichardt— played the glasses and wrote some genuine glass music as well.
The armonica’s premier virtuosa was Mariane Kirchgessner, a blind Austrian woman. Wolfgang Amadeus Mozart composed a beautiful quintet for her (Adagio and Rondo in C, K617) and, presumably as an encore, a Solo-Adagio in C (K617a-K356). Similarly, Vaclav Jan Tomachek was determined to dedicate his wonderful “Fantasia” to her, but she died in 1809, while the work was still in progress, and he finished it at her tomb. These pieces are difficult to learn and perform, but the reward is a deeply moved audience and a superior musical experience.
Musical tastes changed in the 19th century. The symphony orchestra became popular, and improved instruments resulted in previously unheard-of precision and richness of tone. People clamored for sheer virtuosity. The soft and sensitive sound of the armonica was forgotten, as was the art of constructing the instrument. Some composers, such as Ludwig van Beethoven, Gaetano Donizetti, Camille Saint-Saens, and Richard Strauss, still remembered its power and used it in operas or incidental music. But few musicians learned to play the remaining glass instruments, and so the “Armonica” in the scores was gradually replaced by the flute or the celesta.
The current revival of glass music began when the German musician Bruno Hoffman performed the armonica pieces on his "glass harp", which used the technique of the musical glasses. His concerts renewed interest in the sound of glass all over the world. New glass instruments, such as the verrophone and the glass trumpet, were invented.
Even the armonica was revived. The American glass
manufacturer Gerhard Finkenbeiner developed an instrument of pure
quartz, and the German glass musician Sascha Reckert rebuilt the
18th-century armonica using lead crystal.
Today, all the wonderful pieces of glass music again sound
exactly as their creators meant them to sound. Furthermore,
contemporary composers - Harald Genzmer and Fred Schnaubelt in
Germany, Garry Eister and others in America - have written new
glass music, bringing back to life the incomparable voice of the
glasses.