Katabasia or Katavasia is a type of hymn

Hymn

A hymn is a type of song, usually religious, specifically written for the purpose of praise, adoration or prayer, and typically addressed to a deity or deities, or to a prominent figure or personification...

 chanted in the Eastern Orthodox Church

Eastern Orthodox Church

The Orthodox Church, officially called the Orthodox Catholic Church and commonly referred to as the Eastern Orthodox Church, is the second largest Christian denomination in the world, with an estimated 300 million adherents mainly in the countries of Belarus, Bulgaria, Cyprus, Georgia, Greece,...

 and those Eastern Catholic Churches which follow the Byzantine Rite

Byzantine Rite

The Byzantine Rite, sometimes called the Rite of Constantinople or Constantinopolitan Rite is the liturgical rite used currently by all the Eastern Orthodox Churches, by the Greek Catholic Churches , and by the Protestant Ukrainian Lutheran Church...

.

The katabasia is an irmos

Irmos

The irmos is the initial troparion of each individual ode in a canon as chanted in the Eastern Orthodox Church and those Eastern Catholic Churches which use the Byzantine Rite...

 that is sung at the end of an ode

Canticle

A canticle is a hymn taken from the Bible. The term is often expanded to include ancient non-biblical hymns such as the Te Deum and certain psalms used liturgically.-Roman Catholic Church:From the Old Testament, the Roman Breviary takes seven canticles for use at Lauds, as follows:*...

 of the canon

Canon (hymnography)

A canon is a structured hymn used in a number of Eastern Orthodox services. It consists of nine odes, sometimes called canticles or songs depending on the translation, based on the Biblical canticles. Most of these are found in the Old Testament, but the final ode is taken from the Magnificat and...

. The katabasia is chanted by the choir

Choir

A choir, chorale or chorus is a musical ensemble of singers. Choral music, in turn, is the music written specifically for such an ensemble to perform.A body of singers who perform together as a group is called a choir or chorus...

, who descend from their seats (kathismata) and stand on the floor of the church to sing it, whence its name. Katabasia are chanted at Matins

Matins

Matins is the early morning or night prayer service in the Roman Catholic, Anglican, Lutheran and Eastern Orthodox liturgies of the canonical hours. The term is also used in some Protestant denominations to describe morning services.The name "Matins" originally referred to the morning office also...

 and sometimes during other Divine Services

Canonical hours

Canonical hours are divisions of time which serve as increments between the prescribed prayers of the daily round. A Book of Hours contains such a set of prayers....

 such as Compline

Compline

Compline is the final church service of the day in the Christian tradition of canonical hours. The English word Compline is derived from the Latin completorium, as Compline is the completion of the working day. The word was first used in this sense about the beginning of the 6th century by St...

. They are also found at other occasional services such as the Mystery

Sacred Mysteries

The term sacred mysteries generally denotes the area of supernatural phenomena associated with a divinity or a religious ideology.-Pre-Christian religious mysteries:...

 of Unction or funerals

Christian burial

A Christian burial is the burial of a deceased person with specifically Christian ecclesiastical rites; typically, in consecrated ground. Until recent times Christians generally objected to cremation, and practised inhumation almost exclusively, but this opposition has weakened, and now vanished...

.

At Matins, on ordinary weekdays, only Odes 3, 6, 8 and 9 have katabasia. On Sundays and higher-ranking feast days, there will be a katabasia at the end of each ode (these are called Festal Katabasia). Most of the other services which use katabasia will have them only after the 3rd, 6th, 8th and 9th odes.

Ordinary katabasia

On ordinary weekdays (that is, days which do not fall on a Sunday or higher-ranking feast day), the irmos from the canon being chanted is repeated at the end as katabasia. When several canons are tied together, as is normally the case at Matins, only the irmos of the first canon is chanted, subsequent irmoi being omitted. The irmos of the final canon in the string will be chanted at the very end of Odes 3, 6, 8 and 9 as katabasia.

Festal katabasia

On Sundays and feast days, Festal Katabasia are used at the end of each ode. These are not necessarilly the same as the irmoi of the canon. Which particular Festal Katabasia are used will depend upon the liturgical season. The festal Katabasia are used in anticipation of a Great Feast, and throughout its Afterfeast

Afterfeast

An Afterfeast is a period of celebration attached to one of the Great Feasts celebrated by the Eastern Orthodox and Eastern Catholic Churches ....

. During the rest of the year, the Festal Katabasia to the Theotokos

Theotokos

Theotokos is the Greek title of Mary, the mother of Jesus used especially in the Eastern Orthodox, Oriental Orthodox, and Eastern Catholic Churches. Its literal English translations include God-bearer and the one who gives birth to God. Less literal translations include Mother of God...

 (Mother of God) are used.

The following table concerns the chanting of Katabasia on Sundays and Feast Days throughout the year (ordinary weekdays use the Irmos from the last canon chanted on that day).

From	To	Katabasia
January 1	January 14	Theophany
January 15	Apodosis Apodosis Apodosis may refer to:*In linguistics, the main clause in a conditional sentence*In logic, the apodosis corresponds to the consequent; ....  of the Meeting of the Lord §	Meeting of the Lord
Day after Apodosis of the Meeting §§	Cheesefare Saturday	Theotokos Theotokos Theotokos is the Greek title of Mary, the mother of Jesus used especially in the Eastern Orthodox, Oriental Orthodox, and Eastern Catholic Churches. Its literal English translations include God-bearer and the one who gives birth to God. Less literal translations include Mother of God...
Cheesefare Sunday	Bright Saturday	As appointed *
Thomas Sunday	Apodosis of Pascha	Pascha Easter Easter is the central feast in the Christian liturgical year. According to the Canonical gospels, Jesus rose from the dead on the third day after his crucifixion. His resurrection is celebrated on Easter Day or Easter Sunday...  (Easter)
Mid-Pentecost (4th Wednesday of Pascha) °		Mid-Pentecost Mid-Pentecost Mid-Pentecost or Midfeast, also Meso-Pentecost ; is a feast day which occurs during the Paschal season in the Eastern Orthodox Church and those Eastern Catholic Churches which follow the Byzantine Rite....
Sunday of the Blind Man (6th Sunday of Pascha)	Apodosis of Ascension	Ascension
Ascension Day		Pentecost Pentecost Pentecost is a prominent feast in the calendar of Ancient Israel celebrating the giving of the Law on Sinai, and also later in the Christian liturgical year commemorating the descent of the Holy Spirit upon the disciples of Christ after the Resurrection of Jesus...
Sunday before Pentecost (7th Sunday of Pascha)		Pentecost
Saturday before Pentecost	Apodosis of Pentecost	Pentecost
Sunday of All Saints All Saints All Saints' Day , often shortened to All Saints, is a solemnity celebrated on 1 November by parts of Western Christianity, and on the first Sunday after Pentecost in Eastern Christianity, in honour of all the saints, known and unknown...	July 31	Theotokos
August 1	August 6	Exaltation of the Cross
August 7	August 12	Transfiguration Transfiguration of Jesus The Transfiguration of Jesus is an event reported in the New Testament in which Jesus is transfigured and becomes radiant upon a mountain. The Synoptic Gospels describe it, and 2 Peter 1:16-18 refers to it....
August 13		Exaltation of the Cross
August 14	August 23	Dormition
August 24	September 21	Exaltation of the Cross
September 22	November 20	Theotokos
November 21	December 31	Nativity of the Lord

^§ Usually February 9, but if Great Lent

Great Lent

Great Lent, or the Great Fast, is the most important fasting season in the church year in Eastern Christianity, which prepares Christians for the greatest feast of the church year, Pascha . In many ways Great Lent is similar to Lent in Western Christianity...

 begins early, the apodosis may be earlier.

^§§ Usually February 10, but if Great Lent

Great Lent

Great Lent, or the Great Fast, is the most important fasting season in the church year in Eastern Christianity, which prepares Christians for the greatest feast of the church year, Pascha . In many ways Great Lent is similar to Lent in Western Christianity...

 begins early, the apodosis may be earlier.

* Moveable cycle; the exact dates will differ from year to year, depending upon the date of Easter

Computus

Computus is the calculation of the date of Easter in the Christian calendar. The name has been used for this procedure since the early Middle Ages, as it was one of the most important computations of the age....

. During Great Lent

Great Lent

Great Lent, or the Great Fast, is the most important fasting season in the church year in Eastern Christianity, which prepares Christians for the greatest feast of the church year, Pascha . In many ways Great Lent is similar to Lent in Western Christianity...

 the proper Katabasia are found in the Triodion

Triodion

The Triodion , also called the Lenten Triodion , is the liturgical book used by the Eastern Orthodox and Eastern Catholic Churches of Byzantine rite during Great Lent, the three preparatory weeks leading up to it, and during Holy Week.Many canons in the Triodion contain only three odes or...

, during the Paschal season they are found in the Pentecostarion

Pentecostarion

The Pentecostarion is the liturgical book used by the Eastern Orthodox and Eastern Catholic Churches which follow the Byzantine Rite during the Paschal Season which extends from Pascha to the Sunday following All Saints Sunday The Pentecostarion (Greek: Πεντηκοστάριον, Pentekostárion; Slavonic:...

.

° Mid-Pentecost falls on the 4th Wednesday of Pascha and lasts for one week, being a "feast within a feast". The Katabasia of Mid-Pentecost are chanted only on the day of the feast and on its Apodosis

Apodosis

Apodosis may refer to:*In linguistics, the main clause in a conditional sentence*In logic, the apodosis corresponds to the consequent; ....

(the following Wednesday); on the other days of Mid-Pentecost, the Katabasia used are those of Pascha.