The glass armonica was invented by American polymath Benjamin Franklin in 1761. Inspired by musicians who played 'singing glasses' (water-filled wine glasses), Franklin sought to create a more efficient version. His design consisted of a series of glass bowls of varying sizes mounted on a horizontal spindle, which was rotated by a foot pedal. The player would touch the rims of the rotating bowls with moistened fingers to produce haunting, ethereal tones. The instrument became quite popular in Europe, and composers like Mozart and Beethoven wrote music for it. However, it eventually gained a reputation for being 'dangerous.' Rumors spread that the vibrations caused nervous disorders or even madness in performers and listeners, and some suggested the lead in the glass caused poisoning. While these claims were likely exaggerated, the instrument's popularity waned by the 1820s.