What is the primary function of a dominant chord?

The primary function of a dominant chord is to create tension that typically resolves to the tonic chord. This tension is an essential aspect of tonal music. The dominant chord, built on the fifth scale degree of a key, has a strong tendency to resolve to the tonic, or the first scale degree, creating a sense of resolution and completion in the music. This relationship between the dominant and tonic is foundational in Western classical music and many other genres.

In contrast, stability is generally associated with the tonic chord. While harmony can indeed enhance melody or serve as a bridge between sections, these functions do not capture the core role of the dominant chord. Its primary purpose is to build anticipation and prepare the listener for a return to the stability offered by the tonic, making it a crucial element in establishing musical tension and resolution.