Why would a singer feel afraid? She would feel afraid because she does not feel safe. What is it in her that does not feel safe? The illusion that she has control over what happens, how she is perceived, how her voice sounds to others. This illusion, this manufactured safety, is threatened by the truth: that true security, true Geborgenheit, exists only when all of her striving for false safety falls away. Then what is left needs no protection, for it is the very Music of the Spheres, the Energy of Life, Hope, Love, and the greatest Beauty: that which is not created but rather simply allowed to exist. This allowing transforms fear into the most powerful impulse in the universe.
Of course all of this is for naught without a fully-functioning and healthy vocal technique.