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 Guidon
In the 1930s, the paper immersed itself in national issues with a Catholic slant, and loudly protested a proposed divorce bill. Its operations ceased when the World War II broke out, and operations resumed in 1946 under the editorship of Max Soliven. As the paper began to promote peace, its goals expanded from recording Ateneo history-in-the-making and serving to include pieces that were more socially relevant.