Hans Cousto (born 1948) is a freelance natural and cultural researcher and musicologist. After familiarizing himself with the nature of mathematics and geometry at the ETH in Zurich, he explored the structures of sacred buildings and music in India, Afghanistan, Pakistan and Persia. As a result, in 1978 he discovered the universal significance of the law of octaves. He became known above all for calculating the harmonic chamber tones, which he derived from astronomical facts and presented in his fundamental work "The Cosmic Octave" (Synthesis Verlag 1982). Cousto currently lives in Berlin and works in an interdisciplinary manner in the fields of harmonics and music and vibration theory.