Some desert dunes let out a deep, roaring boom when their sand slides

In roughly three dozen deserts and beaches worldwide, sand avalanching down a dune's face produces a sustained boom that can last minutes and carry for miles, known as singing or booming sand. Marco Polo and Charles Darwin both described the eerie sound long before physicists explained it: layers of rounded, uniformly sized grains vibrate together as they slide, turning the dune into a natural resonating chamber. Wet or poorly sorted sand stays silent.

— Ralph A. Bagnold, The Physics of Blown Sand and Desert Dunes — Methuen, 1941
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