Theos Kyrios


Theos Kyrios is a psalm response chanted near the beginning of the Matins service in the Rite of Constantinople, observed by the Eastern Orthodox and Byzantine Catholic churches. It is based principally on Psalm 117, the refrain composed of verses v. 27a and 26a.
Theos Kyrios comes after the Great Ektenia and precedes the apolytikion, and is chanted in the tone of the week. While the Typicon prescribes that the verses should be chanted by the canonarch standing in the center of the nave, in the Byzantine practice the verses are intoned by the psalmist. In common Slavic practice they are chanted by the deacon standing before the icon of Christ on the iconostasis; if there is no deacon, the verses are commonly read by the priest.

Text

The order of Theos Kyrios, as served at Matins is as follows:
They then begin immediately to chant the troparia of the day and the corresponding Theotokion.

Substitutions

Lenten weekdays

On weekdays during Great Lent, Theos Kyrios is replaced by Alleluia. In some places this substitution also occurs on certain weekdays during the lesser fasting seasons: Nativity Fast, Dormition Fast and the Apostles' Fast. This substitution takes place on any day when the order of services follows the Lenten format, for which reason such days are referred to as "days with Alleluia". On days with Allelua, the deacon does not normally serve, so the verses are usually chanted by the priest.
The order of the Lenten Alleluia is as follows:
They then begin immediately to chant the Triadicon, the main text of which differs according to the tone of the week, and the ending of which differs according to the day of the week.

Saturdays of the dead

A different Alleluia is chanted on memorial Saturdays throughout the year. Most of these occur on Saturdays during Great Lent, but there are several others throughout the year as well. This Alleluia is always chanted in the eighth tone, though it may be chanted to a special funeral melody.
They then begin immediately to chant the troparia of the dead:
The same format is followed in the Panikhida.