The origins of liturgical music traditionally date back to St. Gregory the Great (d. 604), who was inspired by the Holy Dove to record the principles of 'Gregorian' chant. The Gradual contained the musical parts of the Missal and was sung from the steps (gradus) of the altar. The Antiphoner contained the musical sections of the Breviary. These terms have become interchangeable in modern times. Because of their size and complexity, these manuscripts were still being handmade in the traditional way for centuries after the introduction of printing. They were boldly hand-written and illuminated on large sheets of sturdy vellum so that the entire choir could read from one book.
This sheet of vellum is part of a Mass For Reparation and includes part of "Zelus Domus Tuae." The sheet has two decorative capital letters illuminated in red, green, and gold, and floral and vine medallions in the borders. Beginning with the large "A" on recto, the text translates as:
Hallelujah, hallelujah. The zeal of Thy house hath consumed Me; and their reproaches against Thee fell upon Me.
Light soiling along the fore-edge of the sheet with a couple of extraneous creases.