glass harmonica
A musical instrument consisting of rotating glass bowls played by touching wet fingers to the rims, producing ethereal, singing tones that were once feared to cause madness.
In Depth
The glass harmonica (or glass armonica) was invented by Benjamin Franklin in 1761 after witnessing a performance on tuned water glasses. Franklin's design mounted 37 glass bowls of graduated sizes on a horizontal spindle rotated by a foot pedal, allowing the player to touch multiple bowls simultaneously with moistened fingers. The instrument produces a hauntingly pure, otherworldly tone with a peculiar ability to bypass the ear's normal directional sense — listeners cannot tell where the sound is coming from. Mozart composed two works for the glass harmonica (K. 617 and K. 356), and Beethoven wrote a piece for it. However, the instrument fell out of favor by the early 19th century, partly due to persistent rumors that its vibrations caused nervous disorders, depression, and insanity in both players and listeners. Modern research suggests the lead content of 18th-century glass may have caused genuine health problems through skin absorption. A small but dedicated community of performers has revived the instrument, and contemporary composers have written new works for it.
The glass harmonica was banned in some German towns in the 1800s because authorities believed its ethereal sound literally drove people insane — a combination of superstition and possible lead poisoning from the glass.