Common Cadence Types

Why This Matters

Cadences are the punctuation marks of music—they tell listeners when a phrase is complete, when to expect more, and how to feel about what they've just heard. On the AP Music Theory exam, you're being tested on your ability to identify cadences by ear, analyze them in scores, and understand why composers choose one cadence type over another. This isn't just about labeling chord progressions; it's about understanding how harmonic motion creates meaning, tension, and release in music.

The concepts at play here include harmonic function, voice leading, phrase structure, and listener expectation. Every cadence type manipulates these elements differently—some deliver the resolution we crave, others deliberately withhold it. Don't just memorize "V–I = PAC." Know what makes a cadence feel conclusive versus open, and why a composer might choose surprise over satisfaction. That deeper understanding is what separates a 3 from a 5.

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Cadences That Resolve: Arriving at Tonic

These cadences bring the listener home to the tonic chord, creating varying degrees of closure. The strength of resolution depends on chord position, soprano note, and which chord precedes the tonic.

Perfect Authentic Cadence (PAC)

• V–I with both chords in root position—this is the gold standard for conclusive endings and the most harmonically stable resolution possible
• Soprano must land on the tonic note (scale degree 1)—this voice-leading requirement is what makes it "perfect" rather than imperfect
• Signals structural closure—used at the ends of phrases, sections, and entire pieces to communicate "we're done here"

Imperfect Authentic Cadence (IAC)

• V–I but missing one PAC requirement—either a chord is inverted, or the soprano lands on scale degree 3 or 5 instead of 1
• Creates softer, less final resolution—useful when you want arrival without full stop
• Often connects phrases within a larger section—think of it as a comma rather than a period

Plagal Cadence

• IV–I motion, known as the "Amen Cadence"—you've heard this countless times at the end of hymns and choral works
• Subdominant function resolving to tonic—lacks the leading tone pull of dominant-based cadences, creating a gentler landing
• Often follows a PAC as a coda gesture—adds warmth and finality after the main cadential resolution

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Cadences That Pause: Ending on Dominant

These cadences stop on the V chord, leaving the listener hanging. They create tension and expectation by denying the resolution to tonic.

Half Cadence (HC)

• Any progression ending on V—the approach chord varies (I, ii, IV, vi are all common), but the destination is always dominant
• Functions like a musical question mark—creates pause and anticipation, demanding continuation
• Appears mid-phrase or at phrase endings—especially common in antecedent phrases of period structures (the "question" before the "answer")

Phrygian Half Cadence

• Specifically iv⁶–V in minor keys—the bass moves by half step ($\hat{6}$ down to $\hat{5}$), creating a distinctive color
• Characteristic stepwise bass descent—this $\flat\hat{6}$–$\hat{5}$ motion gives it a modal, archaic quality
• Common in Baroque music and minor-key works—Bach uses this constantly; learn to recognize its sound

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Cadences That Surprise: Subverting Expectations

These cadences set up dominant-to-tonic resolution but deliver something unexpected instead. They exploit listener expectations built by authentic cadences to create drama and interest.

Deceptive Cadence

• V–vi instead of the expected V–I—the dominant resolves to the submediant, surprising the listener
• Prolongs harmonic tension—delays true resolution and extends the phrase, often leading to another cadential attempt
• Shares a common tone with tonic—vi contains scale degrees $\hat{1}$ and $\hat{3}$, softening the "deception" while still denying full closure

Interrupted Cadence

• V resolving to any non-tonic chord—broader category than deceptive; could go to IV, $\flat$VI, or other unexpected destinations
• Emphasizes the disruption of expected resolution—the term highlights the interruption rather than the deception
• Creates dramatic pivot points—often launches new thematic material or modulations

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Cadences That Evade: Avoiding Closure Entirely

These cadences sidestep resolution altogether, keeping the harmonic motion fluid. They maintain forward momentum by refusing to land anywhere stable.

Evaded Cadence

• Dominant chord moves to something other than expected tonic—but unlike deceptive cadences, the goal is to avoid any sense of arrival
• Creates ambiguity and extends phrases—useful for spinning out musical ideas without committing to closure
• Often involves dominant prolongation—the V chord may return or transform rather than resolve, keeping tension alive

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Quick Reference Table

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Self-Check Questions

1. Both PAC and IAC involve V–I motion. What two specific requirements distinguish a PAC from an IAC?

2. You hear a cadence that ends on the dominant chord with the bass descending by half step. What cadence type is this, and in what key quality (major or minor) does it occur?

3. Compare and contrast the deceptive cadence and the plagal cadence: both involve resolution, but how do they differ in harmonic function and emotional effect?

4. A phrase ends V–vi. Your classmate calls it an "interrupted cadence" while you call it a "deceptive cadence." Who's right, and why might both terms apply?

5. If an FRQ asks you to identify a cadence that "prolongs tension before the final resolution," which cadence types could serve this function, and how do they achieve it differently?