Leaf from an Antiphonal

"Folio extra (61 cm x 36 cm, 20.25" x 14.25"). This single parchment leaf is from a large choirbook—an antiphonal. (The term choirbook refers to a particular format of a codex of liturgical music, intended to be placed on a lectern in the midst of the liturgical choir and to be large enough for those standing in the choir to sing from; an Antiphonal, specifically, contains the antiphons and responsories for the celebration of the daily office.) This particular choirbook is written with eight lines of text and music per page. The text is in black ink in a gothic liturgical hand, with two red initials on each page, for a total of four, the verse and response signs being also in red, and the first letter of the second half of the responsory being overlined in red. The music is on a four-line red staff with black neums, as is usual.nnThe text and music on this leaf are part of the responsory Cantemus domino ... in the eighth mode (beginning with the words "et ascensorem"), the third responsory at Matins for the Fourth Sunday of Lent, the text for which is excerpted from the canticle of Moses (Exod. 15:1-19).nnHesbert, Dorn René-Jean. Corpus Antiphonalium Officii, IV, 6270, var. A ("Currus Pharaonis ..."). Traces of soiling, a little creased, very small tears to one margin from sewing holes, four rectangular spots with remnants of adhesive on verso. Lightly ruled in pencil; gutter edge with a streak of dust-soiling and outer edge with prick marks (for ruling the page) remaining.",Full pdf available, https://dl.mospace.umsystem.edu/mu/islandora/object/mu%3A439211/datastream/PDF/view