Back in my youth (15 years ago), I worked in a bookstore. As most Americans know, bookstores are usually packed near Christmas with frantic folks looking for gifts. The line at the cashregister went half way through the store and people were cranky. I started humming a Carole, my co worker started to sing it. I joined him, and soon the whole line was singing along. We kept going until we no longer had a line of people-maybe we scared away potential customers :-) but people were much less cranky. That's what is cool about live music. It can make people a lot less cranky.