This large bifolio sheet is from a choir book originally used at the Monastery of Santa Isabel la Real in Granada, Spain. The monastery was founded by Queen Isabella of Castile in 1501 for the nuns of Santa Clara. Begun during the Spanish Inquisition, the chapel was finished in 1525, while the cloister was finished in 1592.
The original choir book weighed 125 pounds. The impressively large format was used because it needed to be seen by groups of singers during the church service.