Hallelujah!...but in a Food Court

So, you know Flashmobs? Those things that improv and hijinks groups do where it looks like random people come out of no where, in public places, and perform a dance or some prank.This one, I night say is a little more classy.  A hidden group among food court diners starts to belt out the Hallelujah Chorus. It's hilarious...AND AMAZING! Their voices are stunning.