Chords & Harmony

Plagal Cadence

Definition

A plagal cadence is a phrase ending in which the subdominant chord (IV) moves to the tonic (I), as in F–C in C major. Its soft, settled sound is often called the Amen cadence.

A plagal cadence ends a phrase with the subdominant chord moving to the tonic: IV–I, or F to C in C major. It is gentler than an authentic cadence, because the leading tone, the note that pulls hardest toward home, is missing. The top voice often stays on the tonic while the other notes slide down by step (A to G, F to E), a soft and settled sound.

Two grand-staff panels in 4/4, one bar each. Major: right hand F4 A4 C5 to E4 G4 C5 over bass F2 to C3, with the syllables A-men under the right hand. Minor (borrowed iv): right hand F4 A-flat4 C5 to E4 G4 C5 over F2 to C3. Chord symbols F, C and Fm, C. — Left: IV–I in C major, F to C, with C held on top and the word "Amen" set as hymns often set it. Right: the minor plagal cadence, F minor to C, in which A♭ falls a half step to G.

The "Amen" cadence

Many traditional hymns set their final "Amen" to IV–I, so the plagal cadence is often called the Amen cadence. In that setting it usually comes after an authentic cadence has already ended the hymn, as a quiet postscript. Composers use it the same way elsewhere: a final V–I, then a closing IV–I.

The minor plagal cadence

Borrow the minor iv chord from the parallel minor (F minor in C major) and you get iv–I, in which A♭ sinks a half step to G. It is common in Romantic music and in pop ballads, and it sounds more wistful than the plain IV–I. See borrowed chord.

Plagal cadences in popular music

IV–I is everywhere in rock, folk and gospel music, where it often replaces V–I altogether and gives endings a broad, open feel. Gospel pianists decorate it with passing chords and suspensions, but the basic motion from IV to I is the same.

How to recognize one

Listen to the bass at the end of the phrase. If it moves from the fourth degree to the first (F to C) and the music sounds finished but soft, the cadence is probably plagal. The tonic note held in the top voice is another clue.

Practice with Cadences, Cadences in Every Key and Identify the cadences.

Common questions

Why is the plagal cadence called the Amen cadence?

Because many traditional hymns set the closing word "Amen" to IV–I.

Is a plagal cadence weaker than an authentic cadence?

It usually sounds softer, because the dominant's leading tone is missing. That is why it often follows an authentic cadence as a closing postscript rather than replacing it.