A small vellum leaf from a processional*, written in the 1500's in Spain (?). *Processional. The book containing the principal music sung by the choir during the Divine Office was called "Antiphonary". It was so large that several people could see the text at the same time. In processions smaller books were used for each member of the procession ( the priests and the members of the choir ) as an individual. To keep these books small, very often only the first word, or sentence of a hymn were given. So when the singer saw : "De profundis" he knew they must sing Psalm 129!! ( which he knew by heart of course!)