I've been working on a Mass Setting for a number of years and here is the Kýrie. It is sung at the beginning of Mass after the Confiteor (I confess...)

Although you cannot hear the words (only choirs ahs here), they go:

Kýrie eléison
Christe eléison
Kýrie eléison

Each line is repeated once. I have them sung first by one of the women's sections, then repeated by one of the men's sections. A flute doubles the ladies, and a cello doubles the men. A low handbell intones the root of the chord. I used a lot of open fifths in the choir to give this a Medieval feel.

The English translation is:

Lord have Mercy
Christ have Mercy
Lord have Mercy

The other parts of the Mass Setting I've already written are here:

Alleluia: http://www.furaffinity.net/view/1975013/
Amen: http://www.furaffinity.net/view/13668997/
Agnus Dei: http://www.furaffinity.net/view/7396212/

Dominus tecum