Definitions for Medieval Christian Liturgy
The Eucharist (Mass)

The word Eucharist is taken from the Greek word for thanksgiving. The word Mass is taken from the Latin word for dismissed. Either term (along with Divine Liturgy in the East) designates the central act of Christian worship. The Mass ritually makes present the life, death, and resurrection of Jesus of Nazareth whom Christians understand to be God's annointed (Christ or Messiah).

The essential action of the Mass involves:

the taking up of bread and wine,
the offering up of a prayer of thanksgiving for creation and redemption,
the tearing up of the bread,
the sharing of the bread and wine.

During the ealiest years of the Christian religion, worshippers often (perhaps always?) celebrated these actions within the context of a full meal, itself often called the agape. In any event, by the fourth century Christians no longer celebrated the Eucharist with a full meal. They did, however, continue to incorporate a service of readings, songs, and preaching within the Eucharist.

Although the details of eucharistic ritual varied widely from rite to rite and even significantly within some rites, the basic shape of the Roman Mass as celebrated throughout the Middle Ages can be schematized as follows (the chant forms for the actions follow in italics):

Opening Rites
Blessing of Salt and Water
Sprinkling of Altar(s) with Blessed Water, Asperges me, Vidi aquam
Preparatory Prayers for the Clergy
Solemn Entrance, Introit
Litany, Kyrie eleison
Hymn of Praise, Gloria in excelsis
Opening Prayer
Scripture Proclamation
Prophecy (Hebrew Bible, rare after Antiquity)
Psalm, Gradual, Tract
Procession with the Gospel Book, Alleluia
Creed (Late addition at Rome), Credo
Solemn Intercessions (supressed by Gregory the Great)
The Great Thanksgiving
Offering of Bread and Wine, Offertory
Eucharistic Prayer, Preface Tone, Sanctus
The Lord's Prayer, Pater noster
The Breaking of the Bread, Agnus dei
The Communion, Communion
Closing Prayer
Blessing and Dismissal, Ite missa est

Further Readings