It sounds russian to you because the singing is from Latvia, a baltic state.
During World War II, Latvia was first under Russian control until Germans occupied the country during Operation Barbarossa. SS-Einsatzgruppen were then sent to Latvia; in the second picture from the video there is also SS field post to Latvia.
However, I cant imagine them having many fans there, considering the SS killed many of their people and made them fight the Red Army…
sage because meta