While students at PS 161 in Harlem were dancing to a Beyoncé song in their high school gymnasium, they got a very special surprise when the singer showed up and joined the routine herself (at the 1:35 mark, and note: those kids don't miss a beat when B shows up). It's all a part of the Let's Move! initiative — yes, the very same organization for which Michelle Obama did the dougie — which means this might be one of the best initiatives of all time.