[MysticCat]

You've gotten some good advice.

This may be hard to convey in a post, but try to speak from your diaphragm, not from your throat, especially if you don't have a PA system. What I mean is imagine your voice coming up from your gut, with your diaphragm pushing it up and out and supporting it. Your voice will carry better this way and will not tire as easily. (This is something you'll want to know how to do for the courtroom anyway.) If by chance you happen to have a friend who is a trained singer, ask him or her to show you what I mean.

Good luck!