Antiphonary (or Antiphonal) - Oxford Definition

A type of choir book, used for the singing of the antiphons, the responses for the Divine Office. Although antiphonaries had been in common use since Early Christian times, they only began to be illustrated from around AD 1000. In the Middle Ages rich pictorial cycles were preferred, but from the 14th century word and music took precedence over pictures, the latter confined to historiated initials and grotesques in the margins.