A plagal cadence is a conclusive cadence that moves from the subdominant chord (IV) to the tonic chord (I), often nicknamed the "Amen cadence" for its use at the end of hymns. In the AP Music Theory CED, it is one of the two conclusive cadence types, alongside the perfect authentic cadence.
A plagal cadence is the IV-I progression, the harmonic move from the subdominant chord straight to the tonic. It earned the nickname "Amen cadence" because it is exactly what you hear when a choir sings "A-men" at the end of a hymn. Sing those two syllables in your head and you have already memorized the sound.
In the CED's framework (PIT-2.I.1), every cadence falls into one of two buckets. Inconclusive cadences (half, imperfect authentic, deceptive) leave the phrase feeling unfinished. Conclusive cadences end the phrase with a real sense of arrival, and only two cadences make that list, the perfect authentic cadence and the plagal cadence. What makes the plagal cadence unusual is that it skips the dominant entirely. There is no V chord and no leading tone resolving up to tonic, which is why it sounds gentler and less driven than V-I. The bass moves from scale degree 4 down (or up) to scale degree 1, and the resolution feels like settling rather than landing.
Plagal cadence lives in Unit 4, Topic 4.3 (Harmonic Progression, Functional Harmony, and Cadences). It directly supports learning objective 4.3.B, which asks you to identify cadence types in both performed and notated music, and it connects to 4.3.A because recognizing IV-I means recognizing subdominant function resolving to tonic. Cadence identification is one of the most reliably tested skills in the course. You hear a phrase ending in a listening question, or you see a two-chord ending in a score excerpt, and you have to name the cadence. The plagal cadence is the easy points option in that lineup if you can hear the "Amen" sound and spot IV-I on the page, but it is also a classic trap when it shows up next to authentic cadences in the answer choices.
Keep studying AP Music Theory Unit 4
Visual cheatsheet
view galleryAuthentic Cadence (Unit 4)
The perfect authentic cadence (V-I, both chords in root position, scale degree 1 in the soprano) is the other conclusive cadence in the CED. The PAC is the strong, definitive ending; the plagal cadence is the soft landing. On listening questions, the giveaway is the bass. Scale degree 5 to 1 means authentic, scale degree 4 to 1 means plagal.
Functional Harmony (Unit 4)
Plagal cadences prove that subdominant harmony can resolve directly to tonic without passing through the dominant. That breaks the usual tonic-predominant-dominant-tonic cycle, which is exactly why the plagal cadence sounds different. It is a resolution without the tension of a V chord.
Leading Tone (Unit 4)
The IV chord contains no leading tone, so a plagal cadence resolves to tonic without that half-step pull from scale degree 7 up to 1. The missing leading tone is the technical reason the plagal cadence feels softer than V-I, where the leading tone drives the resolution.
Harmonic Progression (Unit 4)
In part-writing and progression analysis, plagal motion (IV-I) often appears after a perfect authentic cadence as a tag or extension that prolongs the tonic. Knowing this helps you read phrase structure, since the real cadence may have already happened before the IV-I you are looking at.
Plagal cadence shows up most often in cadence-identification questions, both aural and written. A typical multiple-choice stem plays or shows a phrase ending and asks you to name the cadence, with plagal, perfect authentic, imperfect authentic, half, and deceptive as the choices. Practice questions hit this head-on, asking for the chord progression of a plagal cadence (IV-I) versus an authentic cadence (V-I) and contrasting it with the half cadence that ends on V. Your job is threefold. Identify IV-I in notated music, hear the "Amen" sound in performed music, and classify it correctly as a conclusive cadence. In harmonization FRQs, remember that the cadence the prompt usually wants at the end is an authentic cadence, so do not write IV-I where the question expects V-I.
Both are conclusive cadences that end on the tonic, which is why they get mixed up. The difference is the chord before the I. An authentic cadence approaches tonic from the dominant (V-I), with the leading tone resolving up to scale degree 1, so it sounds strong and final. A plagal cadence approaches tonic from the subdominant (IV-I), with no leading tone at all, so it sounds gentler, like an afterthought or an "Amen" added after the music has already ended. When listening, track the bass. If it moves 5 to 1, it is authentic; if it moves 4 to 1, it is plagal.
A plagal cadence is the IV-I progression, where the subdominant chord resolves directly to the tonic.
It is called the "Amen cadence" because it is the harmony behind the sung "A-men" at the end of hymns, which is the fastest way to recognize it by ear.
The CED classifies it as one of only two conclusive cadence types, the other being the perfect authentic cadence (PIT-2.I.1).
Unlike an authentic cadence, a plagal cadence contains no leading tone, which is why it sounds softer and less driven than V-I.
On listening questions, identify it by the bass motion from scale degree 4 to scale degree 1.
Plagal motion often appears after a perfect authentic cadence as a tonic-prolonging tag, so check whether the real cadence already happened.
A plagal cadence is the IV-I progression, where the subdominant chord moves directly to the tonic. The AP CED counts it as one of the two conclusive cadence types, alongside the perfect authentic cadence.
Because IV-I is the exact harmony used for the sung "A-men" that ends traditional hymns. The first syllable sits on the IV chord and the second resolves to I, so singing "Amen" in your head is a built-in mnemonic for the sound.
Conclusive. The CED splits cadences into inconclusive (half, imperfect authentic, deceptive) and conclusive (perfect authentic and plagal). Even though it sounds softer than a PAC, the plagal cadence still ends on tonic and counts as conclusive.
An authentic cadence is V-I and includes a leading tone resolving up to tonic, giving it a strong, final sound. A plagal cadence is IV-I with no leading tone, so it resolves more gently. Listen for the bass, 5 to 1 is authentic and 4 to 1 is plagal.
No. Both are conclusive, but the PAC is the strongest cadence in tonal music because V-I in root position with scale degree 1 in the soprano delivers maximum resolution. The plagal cadence lacks dominant function entirely, so it usually serves as a softer ending or a tag after a PAC.
Connect this key term to the AP exam workflow: review the course, practice questions, and check related study tools.
Review units, study guides, and course resources.
Check this vocabulary in multiple-choice context.
Apply key concepts in written AP responses.
Estimate the exam score you are working toward.
Review the highest-yield facts before practice.