There are ways to summon magical beings: A tooth under the pillow summons the tooth fairy. Clapping saves Tinkerbell. And a gymnasium full of school children line dancing to "Move Your Body" guarantees that Beyoncé shows up. Here's another video of stiletto-clad Beyoncé materializing during a "Move Your Body" workout, this time at P.S. 161 in Harlem. Apparently giving tween girls heart attacks is part of Michelle Obama's Let's Move campaign? Although these girls are actually pretty blasé. I can't decide if they knew that Beyoncé was coming, or were just like, "Oh, like the viral video. Duh."