In pagan times the Slavic Christmas music- Kolyadkas and Shchedrivkas (Traditional Christmas carols in Ukraine and Russia) were a component of sacramentals related with New Year Day and vernal equinox. Later, during the time of the Christianization of Old Russia from Bizantine, Kolyadkas and Shchedrivkas (Ukrainian Christmas carols) became a symbol of Christmas time and other biblical dates and events.
Byzantine priests brought with them the best Bulgarian chanters who made use of Bulgarian melodies (Byzantine melodies adapted to fit the language of the Bulgars, i.e., Slavonic). The Russians were attracted to these melodies which seems only natural considering that the Bulgars and the Russians share a common language and as the time go by organically synthesize
Byzantine tradition and south-Slavic folk-singing culture. Obviously, this has served as the reason of a semantic and stylistic variety of Ukrainian and Russian Christmas music.
Here you can listen and enjoy both authentic, village and church performing of Russian Christmas music and Ukrainian Christmas carols