The now-legendary Antonovka Records have done astounding work documenting music from Russia’s myriad of ethnic communities.  This one is from the so-called “Polish” Old Believers in the Altai region.  From the label’s Bandcamp site:

“The ancestors of the Altai “Polish” Old Believers were peasants of the Vetka-Starodub territory of the priestly Old Believers, who fled from the persecution of the authorities to the Polish–Lithuanian Commonwealth and to the bordering area of the Starodub regiment as part of the Russia. Upon her accession to the throne, Catherine II invited the Old Believers to return to Russia with a manifesto. However, they did not want to. Therefore, in 1764, at the behest of Ekaterina, Vetka was devastated by the troops of Major General Maslov — more than twenty thousand Old Believers were forcibly resettled to Altai and Transbaikalia. In Altai, along the rivers Uba, Ulba, Berezovka, Glubokaya and others, the Old Believers from Vetka and Starodub founded the first settlements in the 1760s, having received the nickname “Polish” in the new place. Now the territory of their residence is divided between Russia and Kazakhstan.”