The song is called Mother Russia and it's on the phenomenal Turn of the Cards album by the group Renaissance which I have no hesitation in recommending.
Legend has it that she answered an ad from a rock band looking for a singer. Annie Haslam had the greatest singing voice I ever heard. I saw Renaissance at the Carnegie Hall concerts around 1976. The band was extraordinarily talented, and her voice really sounds this good live. Unfortunately most of the live Renaissance videos I have seen on YouTube have awful recording qualities, but there are several good live albums, especially the Royal Albert Hall and the Carnegie Hall performances.
The band was moderately successful with their art-rock sensibilities but never broke through with a big US hit. But some of their extended songs--Black Flame, Ashes Are Burning, are highlights of 1970s music. Give it a couple listens before making up your mind.