Singing sand resources worldwide are facing degradation or even loss of voice due to over‑tourism, pollution, and climate change. Understanding their sound‑producing mechanism is urgent for the scientific conservation, restoration, and sustainable utilization of this natural and cultural heritage. Singing sands are classified into desert booming sand, which produces low‑frequency, sustained booming sounds, and coastal singing sand, which emits high‑frequency, short squeaks. The two types differ in particle size, mineral composition, and triggering conditions. This review systematically summarizes the century‑long evolution of singing sand research from the early 19th century to the present, dividing it into three stages: empirical description, experimental exploration, and multi-scale mechanistic modeling. Based on existing discoveries, global and regional distribution maps are compiled, highlighting recent findings of coastal singing sand colonies on Hainan Island, China. Key influencing factors are elaborated, including mineral composition, particle size and sorting, surface cleanliness, moisture content with a threshold effect at approximately 1%, and triggering modes. Classical hypotheses such as elastic cushion, electrostatic or piezoelectric effects, and stick-slip are examined and largely refuted. By contrast, the friction-shearing theory advanced by Bagnold, the surface microstructure of hollows and pores revealed by SEM, and the Helmholtz resonator model proposed by Qu et al. are emphasized as breakthroughs. The review further integrates meso‑scale theories on boundary layer and creep/collision shear as well as macro‑scale waveguide resonance into a multi-scale theoretical framework: from macroscopic energy injection, through microscopic Helmholtz resonance and frequency locking, to waveguide‑mediated amplification and radiation. Future research priorities include quantitative experimental validation of multi-scale coupling, cross‑scale modeling linking particle size and pore geometry to acoustic frequency, systematic global surveys and database construction, environmental vulnerability assessments, and multidisciplinary applications such as biomimetic acoustic materials and environmental sensing. This comprehensive synthesis provides a scientific basis for elucidating the singing sand mystery and guiding sustainable resource protection.