Antiphonarium

Also known as the Antiphonale, the Antiphonarium is a traditional service book containing the antiphons, invitatories, hymns, responds, verses, and, in later usage, the Little Chapters. Originally, antiphons and responds were divided between two distinct volumes, the Antiphonarium and the Responsoriale, as noted by the medieval liturgist Amalarius.

The initial compilation and structural arrangement of the volume are historically attributed to Pope Gregory I, while its later revision is credited to Pope Adrian I. Throughout Western Christendom, early antiphonaries produced across various countries and dioceses reflected considerable diversity in text, structure, and local liturgical usage.