Ernst Chladni at the understanding of electron orbitals. Since at least 1738, a musical instrument called a "Glasspiel" or "verrillon", created by filling beer glasses with varying amounts of water, was popular in Europe. The beer glasses were struck by wooden mallets shaped like spoons to produce "church and other solemn music". Benjamin Franklin was sufficiently impressed by a verrillon performance on a visit to London in 1757 that he created his own instrument, the glass armonica, in 1762. Franklin's armonica inspired several other instruments, including two created by Chladni. In 1791, Chladni invented the musical instrument called the "euphon" (not to
Glass harmonica in his 1919 opera "Die Frau ohne Schatten"), when German virtuoso Bruno Hoffmann began revitalizing interest in his individual goblet instrument version that he named the glass harp for his stunning performances. Playing his "glass harp" (with Eisch manufactured custom designed glasses mounted in a case designed with underlying resonance chamber) he transcribed or rearranged much of the literature written for the mechanized instrument, and commissioned contemporary composers to write new pieces for his goblet version. Franklin's glass armonica design was reworked yet again without patent credit by master glassblower and musician, Gerhard B. Finkenbeiner (1930–1999) in 1984. After thirty