Cadences

A cadence is the pair of chords that ends a musical phrase. It works like punctuation: the same words can end with a full stop, a comma or a question mark, and the choice changes what the sentence does.

The four you need

Perfect (authentic) cadence — V to I

The strongest ending there is. The dominant resolves to the tonic and the phrase sounds closed.

1. GVDominant
   →
2. CITonic

It is strongest when both chords are in root position and the melody lands on the tonic — sometimes called a perfect authentic cadence. Weaken any of those and it still resolves, less emphatically.

Adding the seventh (V7 to I) strengthens the pull further, because the tritone inside V7 has a specific place it wants to go.

Plagal cadence — IV to I

1. FIVPredominant
   →
2. CITonic

Also resolves, but gently. IV contains no leading tone, so there is no semitone straining upward — just a settling. Traditionally called the "Amen cadence" because of its use at the end of hymns.

Imperfect cadence (half cadence) — ending on V

1. CITonic
   →
2. GVDominant

This one ends on the dominant rather than resolving to it. The phrase stops somewhere unstable, so the listener expects more. It is the comma — the standard way to end the first half of a longer structure.

It can be approached from any chord; ending on V is what defines it.

Deceptive (interrupted) cadence — V to vi

1. GVDominant
   →
2. AmviTonic

The dominant sets up a resolution to I, and then goes to vi instead. Because vi shares two notes with I and does tonic duty, it feels like an arrival — just the wrong one.

Composers use it to extend a phrase past the point where it could have ended, which is why it so often appears just before a final, real cadence.

Naming conventions differ

Same four things. The British "imperfect" is a particular trap, because it sounds like it should mean a weak version of a perfect cadence rather than a half cadence.

Hearing them

This is one of the more approachable ear-training tasks, because you are distinguishing four categories rather than twelve. Listen for:

• Does it sound finished? Perfect or plagal.
• Finished with a strong pull? Perfect.
• Finished gently, no leading tone? Plagal.
• Does it sound unfinished? Half cadence.
• Did it sound like it was going to finish and then swerve? Deceptive.