ANTIPHONARY. - The name derives etymologically from *antiphon* (q.v.); today, however, when one speaks of an *antiphonary*, one means the liturgical book containing all the chants used for the Divine Office: thus not only antiphons, but also hymns, verses, etc. Not infrequently, especially among students of Gregorian chant, the term is used to designate the entire body of liturgical chants traditionally attributed to St. Gregory the Great, particularly when the adjective *Gregorian* is added.
The name and content have undergone various changes over the centuries. In the Middle Ages, one finds the designations: *Liber antiphonalis*, *Antiphonalium*, *Antiphonal*, with varying meanings according to time and place. In the 8th century, for example, it referred to the collection of chants used for the Mass, while the collection of chants for the Office was called the *Liber responsorialis*. But from the time of Amalarius, i.e., from the 9th century onward, the book of chants for the Mass is called the *Gradual*, as it is today (or also *Antiphonale Missarum*), while that for the Office is the *antiphonary*. This, however, in turn came to be divided into two distinct books: the collection of chants used for the daytime Offices retained the name *antiphonary*, often with the added epithet *diurnal*, while the collection of chants for the nocturnal Offices took the name *Responsorial*.
This is also the current terminology. Between the 10th and 13th centuries, the *antiphonary* underwent a process similar to that of the Sacramentary, which became the *Missal*. To the primitive *antiphonary-responsorial* were added the Psalter, the Hymnal, then the Lectionary and Alcuin’s Homiliary, and thus arose the *plenary antiphonary*. When, later, copies were made without musical notation, there emerged the *Breviary*, so called because in its relatively small size it was much reduced and abbreviated compared to its predecessor.
