As I described in an article last month, Vespers of Easter Sunday and the days within the octave was celebrated in the Middle Ages according to a special form used only in that period. There were many variations to the ceremony; my article was based on the Use of Sarum, simply because the rubrics of Sarum liturgical books are more thorough than those of most other medieval Uses. When the See of Paris passed over from its Neo-Gallican Use to the Roman books in 1871, a special indult was granted to continue the celebration of Vespers in this form, and this is still done at the church of St Eugène. Here is the video of the full ceremony, from the YouTube channel of our dear friends of the Schola Sainte-Cécile, followed by some pictures; you can follow along in this pdf booklet in Latin and French: https://schola-sainte-cecile.com/programmes/Vepres-stationnales.pdf.
The cantors wear apparelled amices, as was commonly done on the more solemn feasts in the Middle Ages.
The incensation during the Magnificat.
The procession to the baptismal font.
