Probably exactly what Fedor is used to...but I have to say I find it very bizzare
As I understand the above is actually Greek Orthodox and the Below is Russian Orthodox, same Hymn. I cant tell if they are singing the same language, but I dont think so, the one below if far less harsh. Having lived with Greeks in Univeristy, I know that Greek is one of the most harsh sounding Languages in the world
The Orthodox Church grew next to Rome for many centuries, covering the East after the Empire Fragmented into Two. Constentine probably ensured the Orthodox Church when he tried to move the Capital to Constantinople rather then Rome. These people also trace their ancestory back to certain Apostles but unlike the Romans, they do not claim their succession is specifically apostolic and certainly not GODs authorititive voice on the Planet. The Greek and Russian Orthodox as far as I know never had a true split from each other, except for the fact the Greek part was over-run by Islamists after the Fall of Constantinople. Islam made it as far as Greece, but never got to Rome. They also never got that far into Russia. So the Orthodox Church was never truely smushed.
The similarities between Rome and The Orthodox are far closer then Rome and the Protestant and Free Churches. As the Videos show, the Song is a Hymn to celebrate Mary. Notice that the Orthodox Church have depicted Mary in the Colour Purple, and minimal on the blue. Purple is the Colour of Royalty, Red can also indicate Royalty. Rome does not primarily paint her in Purple, but in Blue. to show her humility and submission to Christ, rather then her status as "Mother of GOD" or "Queen of Heaven" though she is refered to by both denominations as both. The other fascinating thing depicted in some of the iconography is the Baby Christ rising out of a Cibourium. The Cibourium is the dish which is used in Communion instead of a plate to distribute the host. This would indicate they hold to transubstantiation...there is even one image where Mary joins him inside the cibourium. This is actually alright, for it shows that any who take communion appear inside the Cibourium with Christ, its more about the communion of Saints then it is about Marian Worship...but all the same without knowing already what the Orthodox believe one might see it as obvious idolitry.
The colour red can also be to do with Martyredom, sacrifice...and although its a leap I guess it could be a form of purity. But White or Gold is tended to show this more, as well as blending with Royalty, those who are actually Holy are usually shown in Gold/Silver, yellow/white. Its not an exact science you understand LOL