WARNING: This Video Contains Portal 2 Spoilers.
By now it's common knowledge that there's a surprising large amount of singing associated with the Portal universe. Both Portal games have special end themes, plus the turrets sing their own opera. Each of those songs has been re-imagined in a whole range of styles.
Now, instead of re-imagining the songs of Portal as pop songs, one musically-inclined fan is imagining pop songs as if they were made for Portal. "If I Were a Core" is a very cleverly rewritten version of Beyonce's "If I were a Boy". It almost makes you feel bad for the little guys...