I have a feeling most people who regularly post on this board already know this, but just for the benefit of the OP and anyone else who might be new to this topic, the above described church…um…isn’t a thing. There is no “Assyrian Orthodox Church”, either as a formal name or in terms of communion, as neither the Oriental Orthodox (non-Chalcedonians) or the Eastern Orthodox (Chalcedonians) recognize the Assyrians/East Syriacs to be Orthodox. There are a small number of ethnic Assyrians who came into union with the Russian Orthodox back in the 1800s sometime following the Treaty of Turkmenchay in 1848, as many Assyrians suddenly found themselves living within Russia (this is how, for instance, the Assyrian nationalist martyr and poet Dr. Freydoon Atouraya, born in Urmia, found himself hanged for his activities in Tblisi, Georgia in 1926, as he had been sent to live with an uncle who was part of the established Assyrian community there). Other than that group, no Assyrians are Orthodox, and certainly the Assyrian Church of the East/East Syriac church is not Orthodox.
The
West Syrians, with the exception of the Maronites and the Oriental Catholic churches that were carved out of preexisting West Syriac churches (the Syriac Catholics and the Syro-Malankara Catholics),
are Orthodox of the non-Chalcedonian/Oriental Orthodox persuasion – i.e., they are in communion with the Coptic, Armenian, and Tewahedo (Ethiopian and Eritrean) Orthodox churches, but not with the Eastern Orthodox (the Byzantine Chalcedonians in Antioch, Palestine, the Slavic lands, Romania, etc.). If you hear of Syrian/Syriac Orthodox Christians or the Syrian/Syriac Orthodox Church, it is referring to this Oriental Orthodox Church traditionally located in Syria, or perhaps its Syriac daughter churches in India, the Malankara Orthodox (Syrian) Church. The Eastern Orthodox/Chalcedonians are a bit different in nomenclature and of course also in practice, as they are referred to most often in English as “Antiochian Orthodox” (after the Patriarchate of Antioch founded by St. Peter and St. Paul and claimed by OO and EO alike), rather than Syriac Orthodox since they have from about the 13th century been Arabized and given up their earlier West Syriac language which the Syriac Orthodox still maintain in worship (together with the Syriac Catholics; the East Syrians like the Chaldeans, the Assyrian Church of the East, and the Syro-Malabar use a different dialect of the same language in worship, and some of them use the modern “Neo-Aramaic” dialects as everyday languages, as do some Syriac Orthodox…but that’s a different dialect than their Eastern friends.)
I know it’s all terribly confusing (probably), but the take home point is: There are no Assyrian Orthodox. There are just…Assyrians. Of course, there is a growing movement to move beyond these various divisions, and I (a non-Syriac) will gladly refer to all collectively as “Syriac people”, since ethnically/culturally/linguistically they are, but anyway…that’s the situation as it stands today.
West Syriac churches (Syriac Orthodox in the Middle East and India);
Syriac Orthodox Qurbono in India (“Qurbono” = West Syriac for “sacrifice/offering”, used to mean liturgy/mass)
Syriac Orthodox prayer in Deir el-Za’faran (Saffron Monastery) in Mardin, Turkey
(I don’t know where good videos are for the Catholic-aligned West Syrians, except for this awesome video of a Syro-Malankara Catholic Qurbono:
youtube.com/watch?v=wEAaAUWd0Jk – the language used here is not Syriac but Malayalam, one of the Dravidian languages of South India that is native to Kerala, where most of the native Indian Syriac Christians of all denominations live…still, what a voice achen has!

)
East Syriac churches (these are exclusively non-Orthodox, either Assyrian Church of the East or of the various RC-affiliated East Syriac churches in the Middle East and India):
Mart Mariam Chaldean Catholic Church opens in Chicago, IL. (the Chaldean Catholic Church, which was created in the 16th century in Iraq following a schism within the Assyrian Church of the East, is the largest single church in terms of members remaining in Iraq)
Syro-Malabar Qurbana (East Syriac Catholics of India…you might want to make sure you’re wearing sunglasses before viewing this…I have no idea what is going on with the background, or why this is so much worse than the Syro-Malankara Qurbono above; sorry, but I don’t really know this church, and this is the first thing that came up)
Assyrian Church of the East celebrates Christmas liturgy in Holland