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
Harmonica were still developed in the 20th century, including the chromatic harmonica, first made by Hohner in 1924, the bass harmonica, and the chord harmonica. In the 21st century, radical new designs have been developed and are still being introduced into the market, such as the Suzuki Overdrive, Hohner XB-40, and the ill-fated Harrison B-Radical. Diatonic harmonicas were designed primarily for playing German and other European folk music and have succeeded well in those styles. Over time, the basic design and tuning proved adaptable to other types of music such as the blues, country, old-time and more. The harmonica was a