Introduce China's five tones and eight tones.

Pentaphone: 1): Also known as pentatonic scale, namely quotient, horn, horn and feather in China's silent scale. The interval between two adjacent notes in a pentatonic scale. Except for the horn and the sign, Yuhe Palace (a palace with an octave height) is three degrees, and the rest are two degrees.

2): Phonological terms. Phonology is divided into five categories according to the pronunciation position of initials, namely, lip sound, tongue sound, tooth sound, tooth sound and throat sound, which is called pentatonic scale. The lightness of five tones was first seen in the five-tone theory before jade. It is also used in China's traditional vocal music theory.

Eight methods: three-point profit and loss method: also known as "five-degree generation method" and "eight-phase generation method" (referring to eight-way interval), which is the method of ancient China calculation rules. If you want to find the fifth note above a known sound on the strings, you can subtract one third from the chord length of the sound. If you want the fourth note below it, you can subtract one third. For example, if the value of gong sound is 3, then 4 is the value of the lower sound (signature sound) and the value of the upper five sounds (signature sound) is 2. The second method was first seen in Guanzi, which was used to achieve pentatonic. Later, I used Lv Chunqiu to find twelve methods.