What is indicated by the functional chord symbol 'IV' in a major key?

The functional chord symbol 'IV' in a major key indicates the subdominant chord, which is built on the fourth degree of the scale. In the context of a major key, the subdominant chord plays a crucial role in harmonic progressions, often serving as a pre-dominant chord that leads to the dominant chord (V) and eventually resolves to the tonic (I). This movement creates a sense of tension and release, which is fundamental to Western music.

For example, in the key of C major, the 'IV' chord would be F major, which consists of the notes F, A, and C. Understanding this relationship enhances one's ability to analyze and create music, as it provides insight into how chords function together within a progression. The subdominant chord often adds richness and depth to the sound, supporting the overall harmonic structure of a piece.

The other choices reflect different functions in harmony, where the tonic represents the I chord, the dominant typically refers to the V chord, and the reference to the minor key context may create confusion, as it does not apply to the identification of the IV chord in a major scale.