136.10 Hz is Cousto's most famous tone: the length of the Earth's year, doubled upward through the octaves until it sounds. He linked it to the note C# and to the chanted syllable OM, and it is the pitch to which many meditation bowls and tuning forks are made. It reads as the planet's own keynote, a slow cosmic cycle made hearable. Practitioners seat it at the heart and treat it as a tone of belonging and rest. In The Cosmic Octave (1978) Hans Cousto set out a simple, exact method: take the period of an astronomical cycle (an orbit, a rotation, a synodic month) and double its frequency, octave upon octave, until it rises into audible sound. The result is a tuning fork for each body in the solar system. This system is the complete table, from the fast tone of Mercury to the slow swing of Pluto. Independent of any tradition, controlled clinical evidence that a specific frequency produces a specific health effect is limited and mixed. Auriviel presents these tunings as music and contemplative practice. This page is for general information and relaxation. Auriviel's frequency music is not medical advice, diagnosis, or treatment, and no health outcome is claimed. If you have a medical concern, please consult a qualified professional.