Phrygian Half Cadence in AP Music Theory

A Phrygian half cadence is a half cadence found only in minor keys where iv⁶ moves to V, producing a distinctive half-step descent in the bass (♭6 down to 5) that echoes the characteristic half-step of the Phrygian mode (PIT-2.I.3, Topic 5.5).

Verified for the 2027 AP Music Theory examLast updated June 2026

What is Phrygian Half Cadence?

A Phrygian half cadence is a specific flavor of half cadence that happens only in minor keys. The progression is iv⁶ to V. Because the iv chord is in first inversion, the bass sits on scale degree ♭6, and it slides down a half step to scale degree 5 when the dominant arrives. That half-step descent in the bass is the whole point. It mimics the signature ♭2-to-1 motion of the Phrygian mode, which is where the cadence gets its name.

Like any half cadence, it ends on V, so the phrase feels open and unfinished, like a musical comma. What makes it 'Phrygian' is not the melody but the bass line. Meanwhile the upper voices typically move up by step against the falling bass, so you get smooth contrary motion baked right into the voice leading. The CED files this under predominant function (PIT-2.I.3) because the iv⁶ chord is doing predominant work, setting up the arrival on V.

Why Phrygian Half Cadence matters in AP Music Theory

This term lives in Unit 5: Harmony and Voice Leading II, specifically Topic 5.5 (Cadences and Predominant Function). It directly supports learning objective AP Music Theory 5.5.A, which asks you to identify cadence types in both performed and notated music. Essential knowledge PIT-2.I.3 spells out the exact formula: iv⁶-V, minor only, alongside the plagal and deceptive cadences. The Phrygian half cadence is also where two big course threads meet. It connects your Unit 1 knowledge of modes and scale degrees to the harmonic-function framework you build in Units 4 and 5. If you can hear or spot that half-step bass descent into V in a minor key, you can name this cadence instantly, and that is exactly the skill 5.5.A is measuring.

Keep studying AP Music Theory Unit 5

How Phrygian Half Cadence connects across the course

Cadence (Unit 4)

The Phrygian half cadence is a subtype of the half cadence, which you first meet in Unit 4. Any phrase ending on V is a half cadence; this one just specifies how you get there (iv⁶ in minor) and what the bass does (falls by half step).

Phrygian Mode (Unit 1)

The Phrygian mode's calling card is the half step between its first two notes (♭2 to 1). The cadence borrows that sound, because the bass motion from ♭6 down to 5 in minor is the exact same half-step descent. The name is a sonic shout-out, not a key change into Phrygian.

Contrary motion (Unit 4)

Textbook voice leading for this cadence has the bass stepping down while an upper voice steps up into the dominant chord. It is a ready-made example of contrary motion, which is why part-writing questions love it.

Dominant Function (Unit 4)

The cadence ends on V, so it lands on dominant function and leaves the phrase hanging. The iv⁶ chord before it is the predominant that aims the harmony at V, which is exactly the function chain Topic 5.5 is about.

Is Phrygian Half Cadence on the AP Music Theory exam?

Expect this in identification tasks tied to LO 5.5.A. You might see a notated excerpt in a minor key and have to label the cadence, or hear a performed phrase and pick the cadence type from a list. The giveaways are a minor key, a phrase ending on V, and a bass line that descends by half step into that V. Multiple-choice questions also probe the voice leading itself, asking how the Phrygian half cadence reflects the characteristic interval of the Phrygian mode (answer: the half-step bass descent from ♭6 to 5) or how it differs from an ordinary half cadence in minor (answer: the specific iv⁶ chord and its stepwise bass approach). No released FRQ has required this term verbatim, but cadence identification underpins the sight-singing and harmonic-dictation skills the exam tests throughout. Memorize the formula iv⁶-V, minor only, exactly as the CED states it.

Phrygian Half Cadence vs Half Cadence

Every Phrygian half cadence is a half cadence, but not the reverse. A generic half cadence is any phrase ending on V, approached from lots of possible chords (I, ii, IV, vi). The Phrygian half cadence is the specific minor-key version where iv⁶ moves to V, so the bass falls by half step from ♭6 to 5. If the key is major, or the bass does not make that half-step descent into V, just call it a half cadence.

Key things to remember about Phrygian Half Cadence

  • The Phrygian half cadence is the progression iv⁶ to V, and it exists only in minor keys (PIT-2.I.3).

  • Its defining feature is the bass falling a half step from scale degree ♭6 to scale degree 5, which imitates the ♭2-to-1 half step of the Phrygian mode.

  • It is a half cadence, so the phrase ends on V and sounds open and unresolved, not finished.

  • The iv⁶ chord has predominant function, meaning its job is to lead the harmony into the dominant.

  • Standard voice leading pairs the descending bass with an upper voice rising by step, creating contrary motion into V.

  • On the exam, identify it by checking three things: minor key, ending on V, and a stepwise half-step bass descent into that V.

Frequently asked questions about Phrygian Half Cadence

What is a Phrygian half cadence in AP Music Theory?

It is a half cadence found only in minor keys where a first-inversion iv chord (iv⁶) moves to V. The bass descends by half step from ♭6 to 5, which gives the cadence its Phrygian-mode flavor. The CED lists it under predominant function in Topic 5.5.

Is a Phrygian half cadence actually in the Phrygian mode?

No. The music stays in a minor key. The cadence is just named after the Phrygian mode because the bass motion from ♭6 down to 5 sounds like the mode's characteristic half step from ♭2 down to 1.

How is a Phrygian half cadence different from a regular half cadence?

A regular half cadence is any phrase ending on V and can occur in major or minor. The Phrygian half cadence is a specific minor-only version using iv⁶ before V, marked by a half-step descent in the bass. Same destination chord, very specific approach.

Can a Phrygian half cadence happen in a major key?

No. The CED is explicit that the iv⁶-V Phrygian half cadence occurs in minor only. In major, the chord before V would be IV, and the bass would not have the half-step ♭6-to-5 descent that defines the cadence.

How do I recognize a Phrygian half cadence by ear or in notation?

Check three things: the key is minor, the phrase ends on the dominant (V), and the bass line steps down a half step into that V chord. In notation, look for iv in first inversion right before the V.