The hills of sun-baked, fine, shifting sand, are rightly considered one of the most unusual and amazing natural creations. Propelled by winds that drive them across the desert, dunes move up to twenty kilometers in a year. And when the sand falls, and the sand grains come into acoustic resonance, the dunes emit sounds similar to a singing human voice or the sound of a cello. The dune is a symbol of mobility and mutability, qualities that our environment demands from us.