in metaphysics, denotes the manner of a thing's existence. See **Metaphysics**, p. 179.

**Mode**, in music, is defined to be a particular manner of constituting the octave; or, it is the melodious constitution of the octave, as it consists of seven essential sounds, besides the key or fundamental.

A mode, then, is the particular order of the concinnous degrees of an octave; the fundamental note whereof may be called the key, as it signifies that principal note which regulates the rest.