Cadences

A cadence is like the musical equivalent of punctuation. Cadences are made up of at least two chords next to each other at the end of a phrase of music. They act as the commas and full stops in a piece of music.

Cadences can make the music feel resolved or finished (like a full stop or period), they can make the music feel like they’re not quite finished and are going on to another point (like a comma), or they can leave the music asking questions and intrigue (like a question mark).

There are four common types of cadences:

a perfect cadence (V-I)
a plagal cadence (IV-I)
an imperfect cadence (I-V, II-V, IV-V)
an interrupted cadence

If you were to see a dominant chord followed by a tonic chord (V-I) at the end of a phrase of music then this would be a perfect cadence. Perfect cadences are the equivalent of a musical full stop. They feel like the music has come to an end as it resolves to the tonic.

In the key of A major, this would be an E major chord (V) followed by A major chord (I):
Another common type of cadence is a plagal cadence. A plagal cadence is a subdominant chord followed by a tonic chord (IV-I) at the end of a phrase of music.

In the key of Bb major, this would be Eb major chord (IV) followed by Bb major chord (I).

Plagal cadences, which are sometimes known as ‘amen cadences’, are also the equivalent of a musical full stop. This is because they too they end on the tonic chord and so feel as if the music has come home and is finished.
Any cadence that finished on the dominant chord (V) is what we call an imperfect cadence (sometimes called a half cadence). It’s sort of like a musical comma as the music doesn’t feel quite finished. Because an imperfect cadence is any one that ends on the dominant chord, there are three different options:
- a tonic chord followed by a dominant chord (I-V)
- a supertonic chord followed by a dominant chord (II-V)
- a subdominant chord followed by a dominant chord (IV-V) In the key of G major
  
  This would be the following in order:
  
  Imperfect cadences tend to come in the middle of a phrase of music (like a comma comes in the middle of a sentence). Then the phrase will often end with a plagal or perfect cadence (like a full stop at the end of a sentence).
Another type of cadence that you might come across is an interrupted cadence (sometimes called a deceptive cadence.

An interrupted cadence is a dominant chord (V) followed by a submediant chord (VI) which, in F major would be a C major chord (V) followed by a D minor chord (IV).

Because you expect the chord V to resolve to the tonic it can sound unfinished and you’re not often expecting it, which is why it’s called a deceptive or interrupted cadence.