"Those Were the Days" bears almost no relation to the Russian text, so I only sing the Russian; otherwise it's like a mash-up, and not the good kind. (TWtD also lacks the wryness of the Russian. I find it just saccharine.) I also hear no appreciable difference in the tune—whether the guy copyrighted his "arrangement" is another story: everyone since the Carter Family does that; gotta grab those ASCAP royalties.