Half Cadence

A half cadence (HC) is a phrase ending on the dominant (V) chord, creating a musical 'comma' that sounds incomplete and demands continuation. In AP Music Theory, it contrasts with authentic cadences (V–I) and includes the minor-only Phrygian half cadence (iv⁶–V).

What is Half Cadence?

A half cadence is what happens when a phrase stops on V instead of resolving to I. Think of it as a comma in a sentence. The music pauses, but nobody thinks the thought is finished. Because V is the most unstable, tension-loaded chord in tonal harmony, ending on it makes your ear expect more music.

The AP CED gives special attention to one flavor of half cadence in Topic 5.5. The Phrygian half cadence moves iv⁶–V and happens only in minor keys. Its signature is the bass line descending by half step (scale degree ♭6 down to 5), which mimics the characteristic half-step motion of the Phrygian mode. That iv⁶ chord is also a textbook example of predominant function, a chord whose whole job is to set up the dominant.

Why Half Cadence matters in AP Music Theory

Half cadences live in Topic 5.5 (Cadences and Predominant Function) under learning objective AP Music Theory 5.5.A, which asks you to identify cadence types in both performed and notated music. That means you need to recognize a half cadence by ear in contextual listening AND by eye in score analysis. Essential knowledge PIT-2.I.3 specifically names the Phrygian half cadence (iv⁶–V, minor only) as a cadence built on predominant function.

Half cadences also matter for phrase structure. The classic antecedent-consequent period works because the antecedent ends with a half cadence (weak, open) and the consequent answers with an authentic cadence (strong, closed). If you can't spot the HC, you can't analyze the period. Voice-leading skills from Unit 4 (objective AP Music Theory 4.5.A) come into play too, since approaching V smoothly, especially in the Phrygian half cadence, depends on stepwise bass motion and careful resolution.

How Half Cadence connects across the course

Authentic Cadence (Units 4-5)

These two are partners, not just opposites. In a period, the half cadence at the end of the antecedent asks a question, and the authentic cadence at the end of the consequent answers it. AP questions about period and double period structure hinge on hearing this weak-then-strong pairing.

Predominant Function (Unit 5)

A half cadence usually doesn't land on V out of nowhere. A predominant chord like ii⁶ or IV sets it up. The Phrygian half cadence (iv⁶–V) is the CED's named example of predominant function ending a phrase, so know that progression cold.

Deceptive Cadence (Unit 5)

Both cadences leave you hanging, but for different reasons. A half cadence stops ON the V chord. A deceptive cadence goes past V but resolves to a substitute chord (usually vi) instead of tonic. Unresolved, but in opposite directions.

Leading Tone (Unit 4)

The V chord at a half cadence contains the leading tone, and that's exactly why it sounds so unfinished. Scale degree 7 is pulling up toward tonic, but the phrase ends before it gets there. The unresolved leading tone is the engine of the half cadence's tension.

Is Half Cadence on the AP Music Theory exam?

Half cadences show up in two main ways. First, cadence identification: multiple-choice questions play or notate a phrase ending and ask you to label it (HC, PAC, IAC, plagal, or deceptive). The giveaway for a half cadence is that the final chord is V, not I. Second, phrase structure: questions about periods and double periods ask you to compare the cadence at the end of the antecedent (typically a half cadence) with the cadence at the end of the consequent (typically a stronger authentic cadence). Practice questions also probe the Phrygian half cadence specifically, asking how its iv⁶–V voice leading differs from an ordinary half cadence in minor and how the descending half step in the bass reflects the Phrygian mode. In free-response harmonization and part-writing tasks, you may need to write a convincing half cadence at a phrase midpoint, which means placing a predominant chord before V and voice-leading into it smoothly.

Half Cadence vs Deceptive Cadence

Both sound unresolved, so they get mixed up constantly. The fix is to look at the LAST chord. A half cadence ends on V itself; the phrase stops before any resolution happens. A deceptive cadence includes V but then resolves it to a non-tonic substitute, usually vi, dodging the expected V–I. Half cadence = stopping at the cliff edge. Deceptive cadence = jumping and landing somewhere unexpected.

Key things to remember about Half Cadence

• A half cadence ends a phrase on the dominant (V) chord, creating an open, unresolved sound like a comma in a sentence.

• The Phrygian half cadence is iv⁶–V, occurs only in minor, and features a descending half step in the bass that echoes the Phrygian mode.

• In period structure, the antecedent phrase typically ends with a half cadence and the consequent answers with a stronger authentic cadence.

• Predominant chords like ii⁶ and IV (or iv⁶ in minor) set up the V chord at a half cadence, which is why Topic 5.5 pairs cadences with predominant function.

• Don't confuse a half cadence with a deceptive cadence: the half cadence stops ON V, while the deceptive cadence resolves V to a non-tonic chord like vi.

Frequently asked questions about Half Cadence

What is a half cadence in AP Music Theory?

A half cadence is a phrase ending on the dominant (V) chord instead of tonic. It sounds incomplete and propels the music forward, and you'll identify it by ear and in scores under learning objective AP Music Theory 5.5.A.

Is a half cadence the same as a deceptive cadence?

No. A half cadence ends on the V chord itself, while a deceptive cadence resolves V to a substitute chord (usually vi) instead of tonic. Check the final chord: if it's V, it's a half cadence.

What is a Phrygian half cadence?

It's a half cadence in minor keys only, moving iv⁶–V. The bass descends by half step from ♭6 to 5, which mirrors the characteristic half-step interval of the Phrygian mode. The CED names it explicitly in essential knowledge PIT-2.I.3.

How is a half cadence different from an authentic cadence?

An authentic cadence resolves V to I and sounds finished; a half cadence stops on V and sounds open. Periods use both, with a half cadence ending the antecedent and an authentic cadence ending the consequent.

Can a half cadence happen in a major key?

Yes. Any phrase ending on V is a half cadence, in major or minor. Only the Phrygian half cadence (iv⁶–V) is restricted to minor, because it needs the minor iv chord and the ♭6-to-5 bass motion.