Many years ago I took a class called "Seeds of Singing" with Susan Osborn, who used to sing with the Paul Winter Consort. She is a firm believer in the old proverb, "If you can walk, you can dance; if you can talk, you can sing." The muscles which control the larynx are among the tiniest in the body, and are incredibly sensitive to thought and emotion (ever get "choked up" or feel a "lump in your throat"?) It's possible to learn to relax those muscles, using her techniques or others, and to let a singing voice come from a previously "monotone" throat. I've heard it happen...and it's amazing.

Aloha,
Mark