Guidonian hand
In Medieval music, the Guidonian hand was a mnemonic device used to assist singers in learning to sight-sing. Some form of the device may have been used by Guido of Arezzo, a medieval music theorist who wrote a number of treatises, including one instructing singers in sightreading. The hand occurs in some manuscripts before Guido's time as a tool to find the semitone; it does not have the depicted form until the 12th century. Sigebertus Gemblacensis in 1105–10 did describe Guido using the joints of the hand to aid in teaching his hexachord. The Guidonian hand is closely linked with Guido's new ideas about how to learn music, including the use of hexachords, and the first known Western use of solfege.
Fork
The introduction of the fork to Western Europe, according to theologian and cardinal Peter Damian, was by Theophano Sklereina, wife of Holy Roman Emperor Otto II, who at an Imperial banquet in 972 nonchalantly produced one, astonishing her Western guests. By the 11th century, the table fork had become increasingly prevalent in the Italian peninsula before other European regions because of historical ties with Byzantium and, as pasta became a greater part of the Italian diet, continued to gain popularity, displacing the long wooden spike formerly used since the forks three spikes proved better suited to gathering the noodles. By the 14th century the table fork had become commonplace in Italy, and by 1600 was almost universal among the merchant and upper classes. It was proper for a guest to arrive with his own fork and spoon enclosed in a box called a "cadena"; this usage was introduced to the French court with Catherine de' Medici's entourage.
Although in Portugal forks were first used around 1450 by Infanta Beatrice, Duchess of Viseu, King Manuel I of Portugal's mother, only by the 16th century, when they had become part of Italian etiquette, did forks enter into common use in Southern Europe, gaining some currency in Spain, and gradually spreading to France. The rest of Europe did not adopt the fork until the 18th century.