This group (like any other one I opened) is dedicated to the comparative research between liturgical traditions. Concerning the subject of the Byzantine heritage of Orthodox chant, methodologies in this field were always forced to be comparative, because the nature of all the different neumes used by notators of Eastern Chant (Armenian, Georgian, ekphonetics, Byzantine notations developed between Antioch, Jerusalem, Sinai and Constantinople, the Slavic notation and its own tonal system etc.) was always to make a difference from the background and the foreground of realisation which was called the "thesis of the melos" in Greek terminology.
I wish not to discuss, if the Coptic tradition was based or influenced by the Hagiopolite oktoechos or not, I just would like to emphasise that this group is open to treat the subject of Coptic and Ethiopian chant as well, as any other Christian tradition of the Mediterranean, including its various exchanges with close Sephardic, Kurdish, Sufi and berber traditions. It does not exclude any tradition without any regard whether it developed dependently or independently of the Byzantine and the Ottoman empire.
Any language is welcome (including Slavonic languages and Greek or any other language), in my experience English is very important to discuss the meaning of Greek terms, and how they were translated and transferred into various languages. It includes all living traditions (also those of Old Believers) and all questions concerning their past back to the earliest tropologia (Iadgari, Šaraknoc', Tropligin), papyrus fragments and lectionaries.