Preserving the Voice
Let me give you one of my greatest secrets. Like all secrets, it is perfectly simple and entirely rational. Never give the public all you have. That is, the singer owes it to herself never to go beyond the boundaries of her vocal possibilities. The singer who sings to the utmost every time is like the athlete who exhausts himself to the state of collapse. This is the only way in which I can account for what the critics term "the remarkable preservation" of my own voice. I have been singing for years in all parts of the musical world, growing richer in musical and human experience and yet my voice to-day feels as fresh and as dear as when I was in my teens. I have never strained, I have never continued rôles that proved unsuited to me, I have never sung when I have not been in good voice.
This leads to another very important point. I have often had students ask me how they can determine whether their teachers are giving them the kind of method or instruction they should have. I have always replied, "If you feel tired after a lesson, if your throat is strained after a little singing, if you feel exhausted, your teacher is on the wrong track, no matter what he labels his method or how wonderful his credentials are."
Isn't that very simple? I have known young girls to go on practicing until they couldn't speak. Let them go to a physician and have the doctor show them by means of a laryngoscope just how tender and delicate their vocal organs are. I call them my "little bits of cotton"; they seem so frail and so tiny. Do you wonder that I guard them carefully? This practice consists of the simplest imaginable exercises—sustained scales, chromatic scales and trills. It is not so much what one practices, but how one practices.