The glass armonica’s ghostly notes will cause insanity in its musicians and listeners! At least this is what was thought to be true in the 18th century. People were frightened by the armonica’s sound due to it’s strange interactions with the human brain and ears (more on this later). Benjamin Franklin invented the glass armonica (above) in 1761 after being profoundly moved by the sounds of the glass harp (below).
The glass armonica’s ethereal notes were said to cause insanity, depression, and marital problems. Via Wikipedia:
One example of fear from playing the glass harmonica was noted by a German musicologist Friedrich Rochlitz in Allgemeine Musikalische Zeitung where it is stated that “the armonica excessively stimulates the nerves, plunges the player into a nagging depression and hence into a dark and melancholy mood that is 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.
The glass armonica’s sound is perceived by human ears differently than other instruments because its range is between 1,000 and 4,000 hertz. When sounds are below 4,000 hertz, the human brain compares “phase differences” between the left and right ears to triangulate the origin of the sound rather than comparing volumes. This causes hearing disorientation and a “not quite sure” feeling about where the sound is coming from. The video below is “Dance of the Sugar Plum Fairy” from the Nutcracker being played on a glass armonica. Relax and enjoy.
Friction instruments of this type are called friction idiophones. The glass armonica is called a crystallophone while the glass harp is called a hydrocrystalophone.