Vocal folds (or chords) tend to thicken as we age, destabilizing pitch. A note sustained begins to jitter/shimmer involuntarily. Lung tissue loses elasticity, the thorax stiffens, respiratory muscles weaken. Though I’ve known this for some time, hearing the quaver in my mother’s voice develop in her late eighties and early nineties, I’m still shocked when the drawn-out two-note chant, Saaaaaat Naaaaam, in yoga class, a clear sonic line I’ve effortlessly sustained for years, crumbles. I have to push air consciously with greater force to repair the brokenness; or the opposite, relax to thin the stream of air, making it continuous, whole again, the sound so small it hides in my throat.