What type of chord is represented by the symbol 'IV'?

The symbol 'IV' refers to the subdominant chord in music theory. In a given key, the Roman numeral notation describes the scale degree on which the chord is built. Specifically, the 'IV' indicates the chord that is constructed on the fourth scale degree of the major or minor scale.

For instance, in the key of C major, the 'IV' chord would be F major, built on the note F which is the fourth degree of the C major scale. The subdominant chord plays a pivotal role in establishing tension and is often followed by the dominant chord (which would be represented by 'V') leading back to the tonic (the 'I' chord). This progression is fundamental in Western music, creating a sense of movement and resolution.

Understanding this function enhances a musician's ability to analyze and create chord progressions effectively.