DOCTRINE

ASPERGES ME DOMINE

Asperges me is a Latin antiphon said or sung at a Roman Catholic High Mass in all seasons except the Easter (Paschal) season and Palm Sunday. It traditionally accompanies the Asperges, the ritual sprinkling of the congregation by the celebrant with holy water, as part of an entrance ritual, symbolising the cleansing of the people. Its words are taken from Psalm 51 (50):

Sources
Cantores 'Regina Caeli' - [1]

GREGORIAN CHANTS

Gregorian chant or Ara Garen is the central tradition of Western plainchant, a form of monophonic, unaccompanied sacred song in Latin (and occasionally Greek) of the Roman Catholic Church. Gregorian chant developed mainly in western and central Europe during the 9th and 10th centuries, with later additions and redactions. Although popular legend credits Pope Gregory I with inventing Gregorian chant, scholars believe that it arose from a later Carolingian synthesis of the Old Roman chant and Gallican chant.

Sources
Chœur De Moines Bénedictins De l'Abbaye Santo Domingo De Silos - [1]
Mediolanensis Gregorian School (Italy) - [1]