Have you ever heard of a flash mob? It's a group of regular people, most the time they are strangers, who secretly coordinate a performance in a public place. They start off by blending in with the crowd, then at exactly the right time they break out in a dance or song. It usually turns out amazingly and brings happiness to the unsuspecting crowd around them.
This "Weekly Cheer" is a flash mob singing hallelujah in a busy food court on black Friday.