Key is the basis of music. Simply put, key refers to the collection of notes used in music. There are two types of keys: major keys and minor keys. Music in major keys sounds bright, high-pitched, and open-minded, giving people a cheerful, cheerful, and energetic feeling; minor keys are relatively melancholy, silent, and mysterious, and are often used to express sadness, affection, and Or a mysterious atmosphere. The key in music has a guiding role, guiding music players to follow the musical rules when playing, and can also emphasize the emotional expression of music.

Tune is not only a concept, but also a manifestation of emotion, because the expression of music is different in different keys. For example, the same song played in different keys will present different feelings; and the same key played in different tracks will present different characters, stories and styles. Therefore, melody, rhythm and harmony, which are complementary to the key, are an important part of the emotional expression of music.

In addition to the above basic functions, key also plays a very important role in music creation. Taking music composition as an example, choosing a key can provide the theme and opening for the entire piece, while also helping the musician shape the specific style and emotional expression of the work. In music learning, it is very important to understand the meaning and characteristics of modulation, which can help students better appreciate and understand the various elements in music.