The fundamental sound is ‘OM.

Everything is vibration. When you chant “OM,” your voice resonates across the universe like the ripples created when a stone is dropped into a pond. This goes on forever.

Each octave of vibration (comparable to do re mi fa so la ti do) flows out of the preceding octave and into the following one: each octave (including both the ‘do’ notes) has half the frequency of the octave above it, and twice the frequency of the octave below it.  This too is a continuum, stretching beyond the limits of hearing and finally beyond the limits of measure. All is a progression along infinite scales. Frequency determines the mode of existence — the manifestation of all phenomena.

Weight Loss Through Yoga, Jewel in the Lotus        page 67