Mass Proper Chants for Epiphany and throughout its Octave; the only difference between the Feast Day of Epiphany itself and the days within the Octave, including the Sunday within the Octave and the Octave Day itself, are that tropes are use on the Feast Day of Epiphany itself.
Communion Antiphon with Psalm verse and Gloria Patri
By the 10th century, at least, a dedicated Feast for Holy Transfiguration was being celebrated. An early witness of this would the 10th century Rheims Sacramentary, BM Reims, MS. 214, on folio page 7v:
The Mass Propers (and Divine Office Propers) we use for the Feast of Holy Transfiguration are, as noted in our books, \derived from these and other Continental sources. One can see the old form of the Mass sheet here.
The above page from the Rheims Sacramentary contains just the Collect, Gospel, Secret, Preface, and Post-Communion as we have it. I believe, when we did some of this research 40 years ago or so, we did find other books, that had variations in the Prefaces, etc. Though searching through old research files and notes on some of the more obscure Masses will take some time.
This is what we have so far using the new corrected Psalter translation:
Thirteenth Sunday after Trinity
Fourteenth Sunday after Trinity
Fifteenth Sunday after Trinity
There are various other scattered files I am collating.
Confession of Faith of St. Mansuetus of Milan and the Synod held in 679, and sent to the Emperor Constantine IV to confirm the Orthodox Fa...
