Sarum Chants for Christmas

I happened to stumble across this video which was posted on YouTube just a couple of days ago, which contains all the proper chants for the Midnight Mass of Christmas according to the Use of Sarum. The recording was made by the Tallis Scholars many years ago, but this video gives the full score of eaxh part. In addition to the regular parts of the Kyriale, (including a troped Kyrie, which was standard in Sarum), it also includes a brief lesson before the Epistle, Isaiah 9, 2 & 6-7, which is sung with a series of tropes, and a sequence. I plan on updating this post with the full text later, but for now, you can read the text of the former in Latin and English at this link, and the sequence in English here.