1. Major key:

The natural major key (often referred to as the major key), that is, the Ionian mode among the medieval modes, is a type of mode. The natural major key contains seven notes, which are Do, Re, Mi, Fa, Sol, La, Si (or Ti) in the solfa. C major is the "simplest" key of the major keys because it is the only major key that does not have any sharps (?) or flats (?), and only the white keys are played on the piano. A minor key that is a minor third lower than a major key is called a relative minor of that major key.

2. Minor key:

Minor key is one of the two tones of modern music relative to the major key. The characteristic is that the first to third note of the scale is a minor third interval. It is usually used to express negative emotions. It is often used to express sad, gloomy, and scary emotions. In animations or movies, it is used as background music in suspense or bloody plots. In games, it is used as battle music or when encountering enemies. Demon King etc.

3. A minor

A minor is a musical minor that starts with the A note and consists of A, B, C, D, E, F, G and A (natural minor). A minor is a key without sharps or flats. Its relative key is C major and its parallel key is A major. Quantz believes that A minor and C minor are more suitable for expressing sad feelings than other minor keys.

Extended information:

1. There are three common major modes:

1. Natural major.

It is also the most commonly used. The scale structure is whole and half, whole and whole and half. It is the basic form of the major key, with brilliant, bright colors.

2. Use major harmonies sparingly.

Lower the VI note of the natural major key by a semitone, so that there is an augmented second between the VI and VII notes. The color is darker, softer, a bit like a minor key.

3. Melody major. Use sparingly.

When the melody goes up, it is the same as the natural major, but when it goes down, the two tone levels of VI and VII are lowered by a semitone.

2. Types of minor keys:

1. Natural minor (natural minor scale): Except for the key signature, no temporary marks are added at all.

2. Harmonic minor (harmonic minor scale): Because of the concept of harmonic leading tone, the leading tone should be a semitone different from the main tone, so in addition to the key signature, the seventh tone of the natural minor scale Raised a semitone, it becomes a harmonic minor scale.

3. Melodic minor (melody minor scale): In addition to the key signature, since the harmonic minor scale raises the seventh tone by a semitone, the difference between the sixth and seventh tone will increase by two degrees. In order to facilitate the development of the melody, when the scale goes up, the sixth-level notes are also raised by a semitone, but it gives people the feeling of a major key. In order to solve this problem, when the scale goes down, the sixth-level notes and seventh-level notes are restored to make them natural. The appearance of the minor scale is called the melodic minor scale.