Singer screws up the Russian National Anthem

This is a video response to a performance of the Russian National Anthem at a mixed martial arts competition. The singer (Larisa Lusta, in Russian Лариса Луста #ларисалуста #луста #larisalusta) decided, bravely or foolishly, to sing without accompaniment, and she had trouble staying in one key. Or even six keys, for that matter. As a mediocre piano player, I thought that analyzing the key changes would be a challenge and a fascinating musical exercise. (to the singer's credit, each time she moved to a new key, she was precisely in tune in the new key)