Ural Russian Folk Chorus

One of four Russian 10-inch records from the 1960's I found had me playing this song over and over: it has a profound energy that captures my imagination. Reminiscent sometimes of a South African choir, these voices come from selected local choirs in the Urals. As I cannot read Cyrillic text, I have no idea what this music is or what the song is about, please comment if you know more...
This recording underwent selected restoration to remove the very worst scratches however was left largely untouched to preserve its character.

Видео Ural Russian Folk Chorus канала Bob Dinwiddy