$~~~~$Benjamin Franklin, one of the Founding Fathers of the United States, was not only a great politician but also a highly accomplished scientist and inventor. Of his many achievements, probably the least well-known are his accomplishments in music. He invented an instrument for which both Mozart and Beethoven composed music—the glass armonica.
$~~~~$In 1761, while living in England, Franklin heard a performer playing musical glasses. Franklin was charmed by the music, but felt that there was a better way to create the same sound. He had a glassmaker create thirty-seven hemispheres made of glass, with each being a different size and thickness to produce different pitches. The glass hemispheres were color coded with paint to identify the notes. Franklin ran an iron rod through a hole in the top of each hemisphere so that they could nest together from largest to smallest. He linked all of this to a device shaped like a spinning wheel, with a foot control that turned the rod, making the glass hemispheres rotate. Franklin moistened his fingers and held them against the rims of the glass hemispheres as they turned, producing a unique sound. He mastered the instrument and took it to parties and gatherings to play for his friends and acquaintances. The instrument became so popular that thousands were built and sold.
$~~~~$But musical fashions changed. Music was moving out of the relatively small halls of Mozart’s day into the large concert halls of the 19th century, and without amplification, the glass armonica simply couldn’t be heard. Concert reviews from the period mourned the fact that the armonica sounded wonderful—only when it could be heard. So, alas, Franklin’s marvelous invention was ultimately abandoned. The popularity of the instrument faded early in the 19th century, but it is still played occasionally today.