I want to add in this thread that I may have a big talk about this, but it's not like it doesn't effect me. I will only sing around people I feel completely and totally safe with. I'm thinking now, and I'd say that's three or maybe four people. When I recorded "Business" above and spoke at the beginning, I was shaking so badly I thought I would drop the phone (which is playing music).
However, my fear is outweighed by how good it feels to sing and share that in the hopes that others will also sing. That's why I started with Amanda Palmer's "Sing" by The Dresden Dolls; it is a tribute to asking people not to be afraid to sing. I'll tell you, whenever I've seen them perform this in concert, they drag a bunch of people up on stage to sing the background. They seek out a range of people, but I have noticed the majority look the most reluctant, including parents accompanying their teens. By the end of the song, though, they are all smiling while they sing.