thumb|350px|Tropligin, (Melkite Use). Depicted are Irmos 705-709 (Syriac Sertâ book script. 11th century, [[Saint Catherine's Monastery, Mount Sinai. Now part of the Schøyen Collection, MS 577.]] Irmologion ( ) is a liturgical book of the Eastern Orthodox Church and those Eastern Catholic Churches that follow the Byzantine Rite. It contains irmoi () organised in sequences of odes (, sg. ) and such a sequence was called canon ( 'law'). These canons of nine, eight, four or three odes are to be chanted during the morning service (Orthros). The name irmologion derives from heirmos (), which means
thumb|350px|Tropligin, (Melkite Use). Depicted are Irmos 705-709 (Syriac Sertâ book script. 11th century, [[Saint Catherine's Monastery, Mount Sinai. Now part of the Schøyen Collection, MS 577.]] Irmologion ( ) is a liturgical book of the Eastern Orthodox Church and those Eastern Catholic Churches that follow the Byzantine Rite. It contains irmoi () organised in sequences of odes (, sg. ) and such a sequence was called canon ( 'law'). These canons of nine, eight, four or three odes are to be chanted during the morning service (Orthros). The name irmologion derives from heirmos (), which means 'link'. The is a melodic model which preceded the composition of the odes. According to the etymology, the book 'collects' ( ) the .
== Musical structure ==
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).