Cadence Types: Authentic, Plagal, Half, and Deceptive

Core Idea

A cadence is a harmonic gesture that punctuates phrases and sections. The four common cadence types are authentic (V-I), plagal (IV-I), half cadence (ending on V), and deceptive cadence (V-vi). Each cadence type has distinct harmonic motion and creates different degrees of closure or tension.

How It's Best Learned

Identify cadence types in hymns, chorales, and songs. Play each cadence type in multiple keys, listening for the characteristic sound and sense of closure or continuation.

Common Misconceptions

Cadences are not always 'perfect' or 'imperfect'—many cadences in music history deviate from textbook examples, and identifying function matters more than classification.

Explainer

A cadence is a harmonic gesture that punctuates musical phrases, functioning like punctuation in prose. Just as a period signals the end of a sentence and a comma signals a pause with more to come, different cadence types signal different degrees of rest, continuation, or surprise. Understanding cadences lets you hear the shape of music — where phrases begin and end, and how much tension or release each boundary carries.

The authentic cadence (V–I) is the most conclusive. The dominant chord (V) has a powerful magnetic pull toward the tonic, driven by the leading tone — the seventh scale degree, which sits a half step below the root and resolves upward with great urgency. When V resolves to I, that tension releases completely. A *perfect* authentic cadence requires both chords in root position with the tonic in the top voice; it sounds completely finished, like the end of a story. An *imperfect* authentic cadence uses an inversion or puts a different chord tone on top, producing slightly less finality.

The plagal cadence (IV–I) sounds gentler and more open than the authentic cadence. Because IV does not contain the leading tone, its resolution to I lacks that half-step urgency. You know this cadence from the "Amen" sung at the end of hymns — it is conclusive, but softly so. Think of it as a sigh rather than an exclamation point.

The half cadence (any chord → V) stops on the dominant and leaves it unresolved. Harmonically, this is a pause on a question mark: the dominant chord demands continuation. Half cadences typically appear at the midpoint of a phrase or section, signaling that more is coming. The choice of what precedes V matters — I–V and IV–V are both half cadences, but with different approaches.

The deceptive cadence (V–vi) is a deliberate surprise. The listener expects V to resolve to I; instead, it moves to the submediant (vi), a chord that shares two of the three tonic notes but is minor rather than major. The effect is a sudden emotional swerve — the phrase does not end where expected, and the music must continue to find its eventual resolution. Composers use deceptive cadences to extend phrases, delay climaxes, or add expressive color at moments that seem about to close.