The substitution of the "Gallican" for the "Roman" version of the Psalter) the Breviary hitherto used exclusively by the Roman court, and with it gradually swept out of Europe all the earlier partial books (Legendaries, Responsories), &c., and to some extent the local Breviaries, like that of Sarum.
This is the very backbone of the Breviary, the groundwork of the Catholic prayer-book; out of it have grown the antiphons, responsories and versicles.
The Proprium de Tempore contains the office of the seasons of the Christian year (Advent to Trinity), a conception that only gradually grew up. There is here given the whole service for every Sunday and week-day, the proper antiphons, responsories, hymns, and especially the course of daily Scripture-reading, averaging about twenty verses a day, and (roughly) arranged thus: for Advent, Isaiah; Epiphany to Septuagesima, Pauline Epistles; Lent, patristic homilies (Genesis on Sundays); Passion-tide, Jeremiah; Easter to Whitsun, Acts, Catholic epistles and Apocalypse; Whitsun to August, Samuel and Kings; August to Advent, Wisdom books, Maccabees, Prophets.
They are: psalms (including canticles), antiphons, responsories, hymns, lessons, little chapters, versicles and collects.
The responsories are similar in form to the antiphons, but come at the end of the psalm, being originally the reply of the choir or congregation to the precentor who recited the psalm.
The versicles are short responsories used after the little chapters.