cadence

In music, two chords that are specially chosen and arranged to give a logical end to a musical phrase or section. Music, like language, has a form of punctuation - with full stops, semicolons, and commas. This ‘musical punctuation’ is found at the end of phrases, which are natural resting points in music, and is called a cadence. Cadences have an important role in helping to establish the tonality of the music.

There are four main cadences in the tonal system: perfect, plagal, imperfect, and interrupted. The perfect cadence (or full close) uses chords V (dominant) and I (tonic). It gives the music a sense of completion or finality and is used when a full stop is needed, as at the end of a piece. The plagal cadence (or weak close) uses chords IV (subdominant) and I (tonic). It also creates a sense of finality and can be found at the end of a piece. It is sometimes called an ‘Amen’ cadence as it is often used at the end of hymns for the harmony of this word. The imperfect cadence (or half close) uses chords I (tonic) and V (dominant). This cadence is a temporary resting place and the music at this point sounds incomplete or unfinished. The interrupted cadence (or false close) uses chords V (dominant) and VI (submediant). As its name suggests, it falsely leads the listener to expect a perfect cadence (V-I) but this is ‘interrupted’ when chord V is followed by another chord. The second chord is usually chord VI although it can be almost any other chord except I (tonic).

Cadences in non-tonal music are achieved through various means. A popular method is where all the parts come to rest on one note (a pitch centre), this being the equivalent of the perfect cadence.