Item is a leaf from a processional gradual, a choir book containing the music used in processions during the Mass. The bookseller's description notes that "the opening leaf of the parent manuscript states this was a 'Gradual for the Carthusian Order'... from the Royal Workshop of Henri II" in Paris. The text of this leaf is for use on Holy Saturday, and is decorated with two large illuminated initials featuring flowers and a strawberry on liquid gold grounds, as well as three smaller initials and three paraphs.
The illuminated C begins part of Exodus 15:1-2: "Cantemus domino...": "Let us sing to the Lord: For he is gloriously magnified: The horse and the rider He has thrown into the sea: My helper and protector. He has brought salvation to me. He is my God, and I will glorify him: The God of my father, and I will exalt him. The Lord has destroyed war: Almighty is His name..."
Beginning with the illuminated letter V: "Vinea...": " My beloved has a vineyard on a very fruitful hill. And he enclosed it with a fence and made a ditch around it, and planted it with the choicest vine..."
A gradual contains the music for the proper of the Mass, the part of the liturgy that varies according to the date (as opposed to the ordinary of the Mass, which is relatively constant). For example, chants for the proper (such as introits, graduals, tracts, alleluia, offertory and communion verses) would vary depending on which holiday or saint's feast day was being celebrated.