Of all my inventions, the glass armonica has given me the greatest personal satisfaction. 


The Glass Armonica

The Glass Armonica

The glass armonica or harmonica is a type of crystallophone, a musical instrument that uses a series of glass bowls or goblets graduated in size to produce musical tones by means of friction.

The earliest form was just a lot of different-sized glasses, played by wetting the finger and rubbing the rims, but Benjamin Franklin invented a new arrangement of the glasses in 1761 after seeing water-filled wine glasses being played in Cambridge in England. The real advantage of this method was that, with the bowls positioned horizontally, the player could play the armonica like a piano, playing up to ten notes at the same time if required.
In Franklin's version, 37 bowls were mounted horizontally on an iron spindle which turned by means of a foot pedal. The sound was produced by touching the rims of the bowls with moistened fingers. Rims were painted different colours according to the pitch of the notes – purple for B, orange for D, etc. 

Popular Music

Franklin played his armonica at dinner parties and their popularity soon took off. Thousands were built and sold, and one factory employed over a hundred people to build the instruments. Many of the performers were women, which was unusual for the period. One of the musicians, Marianne Davies performed all over Europe and even gave lessons to Marie Antoinette.
Composers were also struck by the haunting sounds produced by Franklin's instrument. Mozart wrote two pieces for the armonica, including ‘Adagio and Rondo 617’, and in 1815, Beethoven wrote a short melodrama where a narrator told a story while accompanied by the armonica. Other enthusiasts included Richard Strauss, and Saint-Saëns, who all wrote music for glass armonica. 

In modern times the armonica has been featured in the music of Tom Waits, Linda Ronstadt, David Gilmour, Björk and Robyn Hitchcock.

Excessive Stimulation

At first, the armonica was thought to have a soothing effect, even ‘to cure certain maladies of the blood’, but it soon acquired a sinister reputation. Listening to it was thought to drive you mad, or even summon the dead. In 1798, German musicologist Friedrich Rochlitz wrote: ‘The armonica excessively stimulates the nerves, plunges the player into a nagging depression and hence into a dark and melancholy mood, that it is an apt method for slow self-annihilation. If you are suffering from any nervous disorder, you should not play it; if you are not yet ill you should not play it; if you are feeling melancholy you should not play it’. An instruction manual of 1788 says: ‘If you have been upset by harmful novels, false friends, or perhaps a deceiving girl then abstain from playing the armonica — it will only upset you even more’. After a child died during a recital, the glass armonica was banned altogether in a number of German cities.

Some players complained that the vibrations were entering their fingertips and causing mental anguish. There has been some conjecture that these conditions were caused by lead poisoning that the performers acquired from lead in the glass hemispheres of the instrument.

Franklin himself did not subscribe to the panic; he described the armonica's tones as ‘incomparably sweet’. 


They would talk of nothing but high life, and high-lived company; with other fashionable topics, such as pictures, taste, Shakespeare and the musical glasses.

Ethereal Sound

Why does it sound ethereal? Our ears use different methods to tell where a sound is coming from. Above 4,000 Hertz, we can tell by the difference in volume received by each ear. Below 1,000 Hertz, our ears do it by detecting the ‘phase differences’ of sound waves – that is, we can hear that the peaks and troughs of the sound waves are out of sync. The predominant pitch of the armonica is in between these two wavelengths, so the brain can’t easily interpret where it’s coming from: hence the disturbing ‘ethereal’ quality. 

Marie Antoinette and George Washington were enthusiastic armonica players.

The glass armonica called a hydrodaktulopsychicharmonica in Greek.

Free Invention

At the time of his death in 1790, when more than 5,000 armonicas had been built, Benjamin Franklin had earned nothing from his glass armonica because he refused to patent any of his inventions.

Initially Franklin named the glass armonica the 'glassychord'.

Today there are only a dozen or so glass armonica performers worldwide.

Franklin’s new ‘glassychord’ was premiered in 1762, played by the musician Marianne Davies.