The four voices, or parts, of all harmony, the bass, the tenor, the alto, and the soprana, or the fundamental note, the third, the fifth, and the octave, correspond to the four grades in the series of existences, the mineral kingdom, the vegetable kingdom, the brute kingdom, and man. This receives an additional and striking confirmation in the fundamental rule of music, that the bass must be at a much greater distance below the three upper parts than they have between themselves; so that it must never approach nearer to them than at the most within an octave of them, and generally remains still further below them. Hence, then, the correct triad has its place in the third octave from the fundamental note. Accordingly the effect of _extended_ harmony, in which the bass is widely separated from the other parts, is much more powerful and beautiful than that of _close_ harmony, in which it is moved up nearer to them, and which is only introduced on account of the limited compass of the instruments. This whole rule, however, is by no means arbitrary, but has its root in the natural source of the tonal system; for the nearest consonant intervals that sound along with the fundamental note by means of its vibrations are the octave and its fifth. Now, in this rule we recognise the analogue of the fundamental characteristic of nature on account of which organised beings are much more nearly related to each other than to the inanimate, unorganised mass of the mineral kingdom, between which and them exists the most definite boundary and the widest gulf in the whole of nature. The fact that the high voice which sings the melody is yet also an integral part of the harmony, and therein accords even with the deepest fundamental bass, may be regarded as the analogue of the fact that _the same_ matter which in a human organism is the supporter of the Idea of man must yet also exhibit and support the Ideas of gravitation and chemical qualities, that is, of the lowest grades of the objectification of will. That music acts directly upon the will, _i.e._, the feelings, passions, and emotions of the hearer, so that it quickly raises them or changes them, may be explained from the fact that, unlike all the other arts, it does not express the Ideas, or grades of the objectification of the will, but directly the _will itself_.