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.
A small sheet of vellum from a Processional. Both sides are neatly written with text and four-line music in brown ink with decorative initials in red and blue. The book containing the principal music sung by the choir during the Divine Office was called an Antiphoner or Gradual. This very large book was boldly written so that several people could see the text at the same time. In processions, smaller books were used for each member of the procession.