The inward and essential part of each and every being is composed of fine vibrations, and the external part is formed of the gross. The finer, we name spirit and the grosser matter;the former being less subject to change and destruction and the latter more so
All that lives is spirit and all that dies is matter; and all that dies in spirit is matter and all that lives in matter is spirit
All that is visible and perceptible appears to be living, although subject to death and decay, and becoming every moments resolved into its finer element;but the sight of man is so deluded on account of its wakefulness to the seeming world that the spirit is covered under the garb of matter and its true being is hidden .It is the gradually increasing activity which causes vibrations to materialize , and it is the gradual decrease of the same which transmutes them again into spirit

INAYAT KHAN “Mysticism of sound”