Irmologion

Irmologion (Greek: εἱρμολόγιον heirmologion) is a liturgical book of the Eastern Orthodox Church and those Eastern Catholic Churches which follow the Byzantine Rite. It contains irmoi for the various canons which are chanted during the morning service. The book Irmologion derives from εἱρμός heirmos meaning "link". The irmos is a melodic model which preceded the composition of the odes. Hence, λογεύω logeuō means "to collect", because within the irmologic repertoire there are more canons (or akrosticha) than irmoi.

An important portion of Matins and other services in the Orthodox Church is the canon, a long liturgical poem divided into nine odes. Each ode is made according to a certain irmos, and it is followed by troparia. Sometimes a certain longer irmoi are sung which are called katabasiai because of their descending melos. The troparia sung with the canon are performed out of a textbook (Reader,Menaion) according to avtomela, but the irmoi and katabasiae are chanted by the choir according to irmoi. Since the Irmologion was invented as a chant book provided with musical notation, it only contained the smaller number of heirmoi with those texts which identified them. The other canons and akrosticha were usually collected in a separated text book, and the incipit of a certain heirmos or, in case of troparia the avtomela, indicated the melody which had to be applied for the recitation of the hymns.

Since the Byzantine period, there already developed a soloistic kalophonic way to perform just one ode, but the genre became even more popular and innovative during the Ottoman period following the example of Balasios the Priest. The printed edition of the kalophonic irmologion (1835) is dominated by Ottoman era composers like Petros Bereketis, Chrysaphes the Younger, Germanos of New Patras, and Balasios.

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