To put it bluntly, the so-called "tune" means what sound is the main sound, that is, what sound begins. You can remember this. Ping Jian's order is B, E, A, D, G, C, F, that is to say, if you drop one, you will lose B, if you drop two, you will lose B and E ... and so on. Then remember that the key of one drop is F major, two or more drops. You remember this: B and E are these two drops, right? That's "B flat major". Three flat, B flat, E flat and A flat, that is "E flat major" and four A flat major. Did you see the pattern? That's it. In the same way, there is also the order of ascending and descending, which is reversed: F, A, G, D, A, E and B. How do you remember this? When one is raised, that is, F, it is based on its next sound, that is, "G major"; When F and C are raised twice, the next sound of C shall prevail, that is, "D major"; F, C and G are raised three times. What is your major? It is "a major".
These are the main ones. What happened to the minor? That is, for example, in c major, it can't go up or down. Its scale is 1234567 1, right? Then you will find out who "la" is. You will find that the sound of la is a, then its relative minor is a minor. Lowercase letters are used in minor. That's how other keys are found.
In addition, the major harmonic mode is six tones lower and the minor harmonic mode is seven tones higher. Melody mode in major falls by 6 or 7 tones (only exists in the downward direction, and the upward direction remains unchanged), and melody mode in minor rises by 6 or 7 tones (reverts to 67 tones in the downward direction).
National modes can be divided into five tones, six tones and seven tones. The five tones are Gong, Shang, Jiao, Qian and Yu. It is equivalent to the western model of do re mi sol la. Six tones are added with a "clear angle" or a "change palace", "clear" means raising half a tone and "change" means lowering half a tone, so these two tones are equivalent to f a and Si respectively. Here, these two sounds belong to the partiality, partiality * * *, and there are four. In addition to these two, there is also a leap, which stands for si flat and "sign change", that is, sol flat. There are three seven-tone modes, namely, five-tone plus clear angle and leap, which are called "Le Yan"; Five tones plus clear horns, changing the palace, is called "clear music"; The five-tone plus sign change and palace change are called "elegant music" when judging. For example, the tonic of this song (usually the first and last sounds) is F, which plays the role of business sound, so it is F business mode. As for several tones, you can check how many tones appear in this piece and what they are. Such as "F Shang Six Tones+Changing Palace" and "F Shang Seven Musical Words".