In scales, C is the most stable tone, known as the tonic, and other tones are relatively unstable. The most supportive of the main tone is the upper fifth G and the lower F, which represent the subordinate function and the subordinate function respectively. They are called subordinate and subordinate. A has the closest relationship with the main tone, called the lower baritone, D has the closest relationship with the subordinate tone, called the upper main tone, E and B are called the middle tone and the leading tone respectively.
A chord is composed of three or more sounds, superimposed according to the three-degree relationship.
The triad, 135, on the main tone, is called the “main chord” and is recorded as C.
The trichord formed on the tonic, or 246, is called the “tonic chord” and is recorded as Dm.
The trichord on the baritone, 357, is called the “neutral chord” and is recorded as Em.
The triad formed on the subordinate tone, 461, is called “subordinate chord” and is recorded as F.
The trichord, 572, is called “genus chord” and is recorded as G.
The triad, 613, formed on the lower baritone, is called the “lower middle chord” and is recorded as Am.
C, F, G root to three is big three degrees, three to five is small three degrees, collectively known as “big three chords”. Dm, Em, Am root to three tones is a minor third, three to five tones is a major third, collectively known as the “minor triad”.