Yeah, Becky, sorry about that--I violated one of my own pet peeves: when people post before reading an entire thread. It was a link my brother just forwarded to me a couple hours ago; it must be going viral.

Returning on-topic: A tip for encouraging social singing: Start it by asking someone else to sing or play a specific song. It comes off much better than if you just pipe up yourself out of the blue, and people need to feel that others have given their "permission" and are willing, even eager to listen.