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.
The Downside Ball Game
However, extensive research by the late Dom Lucius Graham OSB has shown that, prior to the building of the present Ball Place, the only version of the game known to Gregorians was not only called 'handball' but was indeed played with the hand. Dom Lucius surmised that the wall's size, and particularly its height, which exceeded the requirements of Handball, prompted the introduction of the bat. Certainly, at the time Dom Stephen Rawlinson came as a schoolboy in 1876, both the hand and the bat varieties were in use, though the former seems to have lost favour and vanished, owing, notes a later commentator, to damage to the players' hands.