Songwriter Keri Hilson — who really should stick to what she does best — performed a live version of “Knock You Down” with Kanye West on Late Night With David Letterman last night. Her performance was subpar – like something you would see on amateur night at the Apollo. Would I be wrong if I said Keri sounds worse than Beyonce did on that fake audio tape of her singing on The Today Show? Sorry, Keri fans, but if you don’t want the truth about your idols don’t come to my blog.