If you're like me, exploring You Tube can be a fun way to discover musicians and regular, everyday people interacting in surprising ways. A trend of late is a "flash mob", defined as "a large public gathering at which people perform an unusual or seemingly random act and then disperse, typically organized by means of the Internet or social media."
Sometimes, it's choral groups performing selections from musicals, or holiday music. Sometimes, like the clip I've selected to share, it's Symphony Orchestras. The players trickle in as their parts are layered in the piece. A crowd grows, enjoying the surprising addition to their day, and then everyone, amazed and blessed, leaves with a new bounce to their step.