The main tone an object or space resonates with.
"Keely's discoveries embrace the manner of obtaining the keynote, or "chord of mass," of mineral, vegetable and animal substance, therefore the construction of instruments by which this law can be utilized is only a question of full understanding of operation of this law." [KEELYS SECRETS - 1888]
"All matter, living and inanimate, has a keynote. Claude Bragdon the architect, who practiced yoga, invited the opera singer Marie Russak to the New York Central Station which he had designed, before it was opened to the public. 'As she stood in the gallery.' says Bragdon, 'she ran up the notes on the diatonic scale in her rich, powerful voice. At the utterance of a certain note the entire room seemed to become a great resonance chamber, reinforcing the tone with a volume of sound so great as to be almost overpowering. The walls, ceiling and the entire building seemed to shout aloud.
"Music, pure, natural, and harmonical, in the true and evident sense of the term, is the division of any keynote, or starting-point, into it's integral and ultimate parts, and the descending divisions will always answer to the ascending, having reference to the general whole. The essence and mystery in the development of harmonies consists in the fact that every keynote, or unit, is a nucleus including the past, the present, and the future, having in itself an inherent power, with a tendency to expand and contract. In the natural system, as each series rises, its contents expand and fall back to the original limit from any point ascending or descending; we cannot perceive finality in any ultimate; every tone is related to higher and lower tones; and must be part of an organized whole." - [F. J. Hughes, Harmonies of Tones and Colours - Developed by Evolution, page 16. See Overtone Series, fundamental]
"The lower diagram, marked C--C, represents their place in the tonal octave of the musical scale. The inert gas is the keynote of the electrical octave just as the note of C in the musical scale is the keynote for that octave. The keynote is omnipresent in all of the elements of matter as well as being omnipresent in the musical scale. By omnipresent we mean that it is in each note as well as its own tone. In music, for example, one is always conscious of
the presence of the keynote, no matter which one is being sounded, nor how many of them. In matter the inert gas is not so mind-consciously aware of its omnipresence but the sudden electrocution of any element, by passing a heavy current through it, will release all of the tones except the eternal keynote. By this process the area of gravity, represented by the hole, is gradually compressed out until the hole is closed up by the united pair and the very dense, hot, solid sphere is the product. The life half of the polarized body, which was created by an effort, comes to an end, and the death half, which requires no effort, begins." [Atomic Suicide, page 162-164]