Benjamin Franklin is the creator of the glass accordion, which produces heavenly notes that once caused fear of madness, writes IFLScience.

Even if you don't recognize this strange device, chances are you've heard the sound it makes. This is a musical instrument invented by none other than Benjamin Franklin.

One of the seven fathers of the United States, Benjamin Franklin's image is still immortalized on the $100 bill, and he was known for his many inventions such as the Franklin stove, the urinary catheter, and the lightning rod. Franklin was also a consummate musician, so perhaps it's not surprising that his imagination was fired when he attended a concert in 1761 and heard an alien sound that inspired him to invent one of his most astonishing creations to date. He called it the glass accordion.

Have you ever rubbed your finger around the rim of a wine glass to hear the sound it makes? That is exactly the sound of the glass accordion.

When Franklin saw an orchestra musician playing on wine glasses filled with water at a concert in 1761, he probably thought, "I can do better than that." Of course he went a step further, with a total 37 glass plates, which he mounted on a rotating mechanism that the musician could operate using a foot pedal. His instrument was easier to handle, and the musician could produce up to 10 notes at once. And so the glass accordion was born.

In addition to classical music, Franklin's invention also found its place in the music of Tom Waits, David Gilmour and Bjork.

But still, there is a dark side to the music of the glass accordion, which is why some call it that "the most dangerous instrument in the world".

In the 18th century, the glass accordion was feared to have the power to drive the listener insane. At that time, the German musicologist Friedrich Rochlitz advised people to avoid playing it.

"The harmonica overstimulates the nerves, plunges the player into a dull depression, and from there into a dark and melancholy mood which is a suitable method of slow self-destruction," said Friedrich.

Modern musicologists believe there is an explanation for why the sounds of the glass accordion can have a disorienting quality. The instrument produces sounds at frequencies between 1.000 and 4.000 hertz, approximately. At these frequencies, the human brain struggles to pinpoint where the sound is coming from. This may explain why, at least for some people, listening to this music can be an unsettling experience.