The Liturgical Book of the Oktoechos. Function, Forms, and Manuscript Tradition

This chapter offers a detailed investigation into the liturgical book known as the Oktoechos within the Byzantine tradition, focusing on its function, structure, and manuscript history. The Author clarifies the multiple meanings of the term "oktoechos" in Byzantine sources, distinguishing between the musical eight-mode system, the weekly liturgical cycle, and the book itself. The study explores the evolution of the Oktoechos from its early roots in the Jerusalem liturgical tradition, particularly through Georgian and Greek sources such as the Old and New Tropologion. The work highlights the interplay between the Oktoechos and other liturgical books like the Menaion, Triodion, and Pentekostarion, and traces the contribution of major hymnographers including John of Damascus and Andrew of Crete. Special attention is given to terminological ambiguities, manuscript variants, and regional adaptations. Overall, the chapter presents a nuanced reconstruction of the development and standardization of this central Byzantine liturgical book.