What are the differences and specific usages of the concepts of harmony, chorus and accompaniment?

In the category of harmony acoustics, there are many types of harmony, such as functional harmony, national harmony, counterpoint harmony and modern harmony. Functional harmony (also known as traditional harmony) was created by European classical music school and Romantic music school.

Harmony is the pitch organization form of multi-part music and one of the basic means of music expression. As far as the general concept of composition theory is concerned, harmony is a technical category corresponding to counterpoint (commonly known as polyphony). Harmony has always been regarded as the basis of counterpoint in music practice for more than one hundred years before19th century.

Since17th century, due to the gradual development of melody music, the role of harmony has become more and more important. Its role in music has three aspects:

(1) combination of parts. On the basis of unified harmony, all the voices are combined with each other to form a harmonious whole.

② The structure and function of music. Harmonic progression, group gathering and tonal layout play an important role in the composition of music forms.

③ The expressive function of content. Through the color and texture of harmony, the musical image is shaped and the musical content is expressed. The treatment of harmony is an important writing skill in music creation, and it is also the basis of other composing techniques such as counterpoint, orchestration and form. Sometimes, tunes also come from harmony.