Now if I were to ask you if the Kyrie Eleison (Translated “Lord Have Mercy”) were part of the Penitential Rite most likely you’d say “Of course it is.” After all we are asking God’s mercy. But interestingly enough it serves more as an acclamation of praise both historically and liturgically as we shall see.
The History of the Kyrie – the Kyrie is often thought of as a part of the penitential rite but this is not necessarily the case. The General instruction describes it this way: “After the penitential act the Kyrie Eleison is begun unless it has already been used in the penitential act. It is a song in which the faithful acclaim the Lord and ask for his mercy therefore it is usually to be sung by all, that is by the congregation as well as the schola or cantor.” Hence the Kyrie may or may not be a part of the penitential rite. As we shall see in its origins, the Kyrie is historically more a hymn of praise than a penitential act.
The early history may be seen in pagan antiquity. There was the custom of imploring the help of the gods with the phrase “eleison.” Likewise, the phrase was used in reference to the emperor. A singer would announce some praise of the emperor and the people would respond with this or another cry of homage. However, there are also scriptural roots in the Old Testament. For example, in the Greek translation of the O.T. (the Septuagint) there are many phrases particularly in the psalms such as, “eleison me Kyrie.” (Have mercy on me Lord) (Psalm 6:2 inter al.) Also in the New Testament there are many places where the phrase is used: Son of David have mercy on us. This phrase is indeed quite common in the N.T. Nevertheless Kyrie litanies where not common in the Church until after the Age of Constantine (4th century) likely due to their connections with paganism. After the persecutions ended and paganism move to the background it was deemed appropriate to use these forms of courtly honor to honor the Lord.
The entrance of the Kyrie into widespread use in the Church may be described as follows. The practice was first reported in use in Jerusalem wherein the phrase “Kyrie Eleison” was sung in response to a series of petitions sung by a deacon. This practice was noted both within Mass (where it took place after the Gospel) and outside of Mass (for example at Vespers). The practice was brought back to the West probably by returning pilgrims and it was considered widely appealing. Eventually its use came to be quite universal in the Church. In some areas it was located at the beginning of Mass while in other areas it had its place after the Gospel. Eventually it came to be generally located at the beginning of mass. It was specifically introduced into the Mass by Pope Gelasius in the later half of the 5th century. The form of the Kyrie was retained as a litany of praise and supplication before God and these prayers grew in elaborateness. You can see the Kyrie Litany of Gelasius HERE .
In a desire to simplify and shorten the liturgy, Pope Gregory the Great in the early 7th century removed the prayers and kept only responses Kyrie eleison and Christe eleison. First this was done only on ordinary days, leaving the prayers on more solemn feast. Later their use faded completely leaving only the responses. The Kyrie responses were said at first only by the people. But gradually the priest and the people began to alternate, responding back and forth with a nine-fold response (KKK,CCC,KKK). Gradually the singing of these became more elaborate and tended to be done by a choir of trained singers. In the Tridentine mass the Kyrie was recited by the priest alternating with the servers in the ninefold Kyrie. In solemn Mass it was also sung by the Choir or schola. But it was NOT considered part of the penitential rite which had take place at the foot of the Altar and was separated from the penitential rite by several things: the ascent of the altar steps, kissing the altar, possibly incensing it, making the sing of cross to begin Mass, reading the Introit (entrance song) and only then reciting the Kyrie.
Today it is returned to having the priest and people alternate in what is usually a sixfold Kyrie. There is also the option of introducing the Kyrie into the penitential rite in which case it is returned to its older litany-like form with certain petitions and/or praises attached to each Kyrie and Christe.
Complicated enough?? The Kyrie has somewhat of a dual personality. It may serve either as a penitential rite or a hymn of praise. However, even when it is used as a penitential act, we still give glory to God on account of his great mercy. The history of the Kyrie Litany gives rise to an appreciation of the source of our practice today of the intercessory prayers after the Creed (sometimes called the “prayer of the faithful”). In fact, it should be remembered that the response “Kyrie Eleison” may in fact be made instead of “Lord hear our prayer.” More will be said of this later on.
Here is a polyphonic Kyrie, a Kyrie in Gregorian Chant, and a Modern Kyrie litany: