It is generally thought that Chinese music is homophonic. In instrumental music, the players tend to play in unison, and in vocal music, the instrumental accompaniment closely follows the pattern of the singing. The science of harmony, or the system that governs the combining of the intervals as applied in European music, was not known to China in the past. In fact, very little was said in the long history of Chinese music about the theory of combining the intervals.

However, unison is not to be regarded as the sine qua non in Chinese instrumental and vocal music. In many types of Chinese folk music, one finds that the players or singers do not adhere strictly to unison but vary their parts in juxtaposition and in relay. Frequently, the players resort to embellishing the melody and the more skilful ones will embark on extemporization, giving rise to heterophonic effects. The practice of embellishment and extemporization is intended to avoid monotony in ensemble playing and to show off the skill of the player. But in specific cases, different parts are planned for the singers and players to perform.