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
Social class in 18th-century Spain Social class in 18th-century Spain The social structure of Spain in the 18th century continued to be based upon nobility and peasantry. However, the period also saw the growth of a middle class, centred upon the growing bureaucracy associated with Bourbon rule, and upon a limited development of commerce and industry. In Spain at this period there were a large number of nobles. Some of them were rich while others were poor workers. Although their number decreased during the second half of the century, they continued numerous, due in part to the large number of "hidalgos" in the north of