Anyone can test this with a pop bottle and a small amount of embouchure control: flatten your lips and blow across the top of the bottle. When it’s full you get a whistle. As you drink the soda down, the sound deepens. The principle is just as true inside your body as out in the world—a soprano is born, and you can see it in her silhouette. More often than not she’s small, like me. Her thin neck means that her vocal cords are slender and tightly packed together. They resonate at a high frequency when air rattles through them. Her jaw is strong, the mouth an echo chamber. Every tuck and fold a part of the instrument. As a singer you have to be careful with your body the same way you’d be careful transporting crystal or glass. When the temperature varies too drastically, molecules shift and expand. Things shatter. The pen in my purse spills ink everywhere during altitude changes; and after plane rides longer than two hours, I need to avoid citrus fruits for a week, drink only herbal tea.
