L'estro armonico National Library of Wales in Aberystwyth. The 1797 Encyclopædia Britannica records that the fifth concerto was also played on an Irish variant of Benjamin Franklin's celebrated invention, the glass harmonica. Under the entry for "Harmonica" or "Armonica", a 35-glass harmonica is described, about which its inventor, the Dublin physician Edward Cullen, writes: There were numerous arrangements for keyboard instruments in the eighteenth century, as described in the next section. One surviving eighteenth century transcription of Op.3, No.3 has been interpreted as an arrangement for glockenspiel. Themes from movements in the concertos were borrowed by other composers for vocal works: the
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