Glass harmonica Franklin and a fellow of the Royal Society, extended the experiments of Pockrich, contriving a set of glasses better tuned and easier to play. During the same decade, Christoph Willibald Gluck also attracted attention playing a similar instrument in England. Benjamin Franklin invented a radically new arrangement of the glasses in 1761 after seeing water-filled wine glasses played by Edmund Delaval at Cambridge in England in May 1761. Franklin worked with London glassblower Charles James to build one, and it had its world premiere in early 1762, played by Marianne Davies. Writing to his friend Giambatista Beccaria in Turin, Italy,
Glass harmonica and locate ranges of sounds. Above 4 kHz people primarily use the "loudness" of the sound to differentiate between left and right ears and thus triangulate, or locate the source. Below 1 kHz, they use the "phase differences" of sound waves arriving at their left and right ears to identify location. The predominant pitch of the armonica is in the range of 1–4 kHz, which coincides with the sound range where the brain is "not quite sure", and thus listeners have difficulty locating it in space (where it comes from), and discerning the source of the sound (the materials and