As an Easter gift to readers, we are happy to offer this Kyriale supplement published in 1934.
[Download here: Supplementum ad Kyriale.]
Anyone who studies the Troparia of the Spanish archives comes across a number of chants that are commendable for both their antiquity and their elegant melody, but which are lacking from the “Ordinary of the Mass” of the Roman Graduals according to the Vatican typical edition.
The perspicacity of our brother Dom Casiano Rojo  discovered this and, in order to supply this defect, he edited a small appendix to the Kyriale for Spain.
But the edition of this booklet having already been depleted, we now offer this more ample supplement, so that just as studies of Spanish codices have recently multiplied, so also the number of melodies which in Spain were once more copious, may be increased.
We have decided to omit from this edition, however, certain chants that are found in many German, French and Italian codices, in all likelihood because they were composed already in the 10th or 11th century by the monastic masters of melody working in the Abbey of St. Martial of Limoges.
When the same melody appears with several variations, we have seen fit to choose the one that excels the others in both elegance and antiquity.
 Dom Casiano Rojo Olalla (1877-1931), prior of Santo Domingo de Silos.