Review AP Music Theory Unit 5 to build fluency with predominant function, the vi and iii chords, cadence types, and all four types of second-inversion chords. This unit connects the tonic-dominant framework from Unit 4 to the richer harmonic vocabulary you need for part-writing, analysis, and dictation.
Use this page to review every topic from 5.1 through 5.7, check your understanding of voice-leading rules, and identify the chord types and cadences most likely to appear on the exam.
Unit 5 is where harmonic progressions get their full shape. You move from the two-function tonic-dominant world of Unit 4 into a three-function model: tonic, predominant, dominant, tonic (T-PD-D-T). The predominant area is filled by IV, iv, ii, ii°, and their seventh-chord versions, all of which prepare the dominant and intensify the sense of key.
Predominant chords (IV, iv, ii, ii°) sit between tonic and dominant to intensify the establishment of key. Recognizing this three-function order lets you label harmonic function accurately in both score analysis and listening tasks.
Second-inversion triads are restricted to four specific uses: cadential, neighboring (pedal), passing, and arpeggiated. Each type has its own beat placement, doubling rule, and voice-leading pattern, and mixing them up is a common part-writing error.
The deceptive progression (V moving to vi instead of I) and the Phrygian half cadence (iv6-V in minor) are named progressions you must identify by ear and in a score. Both involve predominant or dominant function resolving in an unexpected direction.
Every task in Unit 5 depends on understanding that predominant chords do not resolve tension on their own; they build it before the dominant does. Whether you are writing four voices, detecting errors, or labeling a cadence, the question is always the same: which functional area does this chord belong to, and does it move correctly to the next one?
Introduces the T-PD-D-T phrase model and the two main predominant chords: subdominant (IV/iv) and supertonic (ii/ii°). Covers voice leading from predominant to dominant and Roman-numeral analysis of these chords in major and minor keys.
Examines the submediant chord as a tonic substitute and weak predominant, with emphasis on the deceptive progression (V-vi) and the voice-leading requirements when the leading tone resolves into vi.
Covers ii7 and iiø7, their inversions in figured bass, and the rule that the chordal seventh resolves down by step, including the retention option when moving to a cadential six-four.
Explains why the mediant triad is rare in 18th-century style, how iii prolongs tonic in major, and how III in minor most often represents the relative major key.
Identifies the plagal cadence (IV-I, iv-i), Phrygian half cadence (iv6-V in minor), and deceptive cadence (V-vi) alongside PAC, IAC, and HC, with focus on recognizing each type by ear and in a score.
Establishes that the cadential six-four functions as dominant embellishment, not tonic, and requires the sixth and fourth above the bass to resolve down by step on a metrically strong beat.
Covers the neighboring (pedal), passing, and arpeggiated six-four types, including their distinctive bass motion, upper-voice behavior, beat placement, and doubling conventions.
This snapshot uses Fiveable practice activity to show where students tend to miss questions and which review moves are worth prioritizing first.
Across 145 multiple-choice practice attempts for this unit.
Practice activity included in this snapshot.
Across 1 scored free-response attempts for this unit.
Review Adding Predominant Function IV (iv) and ii (ii°) to a Melodic Phrase with attention to how the concept appears in AP-style source and evidence questions.
Review Cadential Six-Four Chords with attention to how the concept appears in AP-style source and evidence questions.
Predominant chords occupy the harmonic area between tonic and dominant. Adding them to a phrase produces the T-PD-D-T shape, which intensifies the sense of key far more than a plain T-D-T progression. The two main predominant chords are the subdominant (IV in major, iv in minor) and the supertonic (ii in major, ii° in minor). Both typically resolve to V or V7 through descending-fifth root motion or stepwise voice leading.
| Chord | Key type | Quality | Typical resolution |
|---|---|---|---|
| IV | Major | Major triad | V or V7 |
| iv | Minor (or mixture) | Minor triad | V or V7 |
| ii | Major | Minor triad | V or V7 |
| ii°6 | Minor | Diminished triad, first inversion | V or V7 |
The submediant chord (vi in major, VI in minor) has two distinct roles. As a tonic substitute, it shares two common tones with I and can extend or prolong the tonic area. As a weaker predominant, it can move toward V. Its most tested use is the deceptive progression, where V resolves to vi instead of I, avoiding the expected authentic cadence and requiring careful voice leading: the leading tone still resolves up to scale degree 1, which becomes the third of vi.
| Function of vi | Context | Typical progression |
|---|---|---|
| Tonic substitute | Extends tonic area | I - vi - IV or I - vi - ii |
| Weak predominant | Moves toward dominant | vi - V |
| Deceptive target | Follows dominant | V - vi (deceptive cadence) |
Predominant seventh chords (ii7 in major, iiø7 in minor) do the same harmonic job as predominant triads but add a chordal seventh that must be handled carefully. The chordal seventh resolves down by step to the third of V. One exception: when ii7 moves to a cadential six-four, the seventh can be held in the same voice for one chord before resolving down. Inversions of ii7 are labeled with figured bass: ii6/5, ii4/3, and ii4/2.
The mediant triad (iii in major, III in minor) is the diatonic chord built on scale degree 3, and it appears rarely in 18th-century harmonic progressions. In major keys, iii is a minor triad that can prolong the tonic area by sharing two common tones with I. In minor keys, III is a major triad that most often represents the relative major key rather than functioning as a standard diatonic chord. Do not treat iii as a default predominant; recognize it when you see it and label its function accurately.
| Chord | Key | Quality | Primary role |
|---|---|---|---|
| iii | Major | Minor triad | Rare; tonic prolongation |
| III | Minor | Major triad | Represents relative major key |
Several cadence types use predominant function directly. The plagal cadence (IV-I or iv-i) moves from subdominant to tonic and is often heard as an 'amen' ending. The Phrygian half cadence (iv6-V) occurs only in minor and is named for the half-step motion in the bass from scale degree 4 down to scale degree 5. The deceptive cadence (V-vi or V-VI) avoids the expected tonic resolution. These join the authentic cadences (PAC, IAC) and half cadence (HC) you already know from Unit 4.
| Cadence type | Progression | Key restriction | Sense of closure |
|---|---|---|---|
| Plagal | IV-I or iv-i | None | Moderate; soft |
| Phrygian half | iv6-V | Minor only | Open; distinctive bass motion |
| Deceptive | V-vi or V-VI | None | Interrupted; no closure |
| PAC | V(7)-I, root position | None | Strongest closure |
| Half cadence | Any chord to V | None | Open; expects continuation |
The cadential six-four (I6/4 or V6/4-5/3) is a second-inversion tonic triad that appears immediately before the dominant at or near a cadence. Despite containing the notes of the tonic triad, it does not function as tonic. It functions as an embellishment of the dominant: the bass holds scale degree 5, and the sixth and fourth above the bass resolve down by step to the fifth and third of V (or V7). The cadential six-four always falls on a metrically stronger beat than the dominant chord that follows it.
Beyond the cadential six-four, three other types of second-inversion chords are permitted in tonal music, each with its own voice-leading pattern and beat placement. All three are embellishing chords that decorate a stronger harmony rather than producing real harmonic motion. Knowing which type you are looking at depends on what the bass and upper voices are doing.
| Type | Bass motion | Upper voices | Beat placement | Doubling |
|---|---|---|---|---|
| Cadential | Stationary on scale degree 5 | Resolve 6 down to 5, 4 down to 3 | Strong | Bass (fifth of chord) |
| Neighboring (pedal) | Stationary | Move to upper neighbors and return | Weak | Bass |
| Passing | Stepwise scale fragment | Stepwise motion | Weak | Fifth of the chord |
| Arpeggiated | Arpeggiates triad | Static | Follows arpeggiation | Bass |
Try AP-style multiple-choice questions and written prompts after you review the notes.
| Term | Definition |
|---|---|
| Subdominant chord | The chord built on scale degree 4 (IV in major, iv in minor); a primary predominant harmony that moves to the dominant to build tension before a cadence. |
| Supertonic chord | The chord built on scale degree 2 (ii in major, ii° in minor); a strong predominant because its root lies a fifth above the dominant, producing smooth circle-of-fifths motion. |
| Chordal Seventh | The note a seventh above the root of a seventh chord; in predominant seventh chords like ii7 and iiø7, it must resolve down by step to the third of the dominant chord. |
| Submediant chord | The chord built on scale degree 6 (vi in major, VI in minor); functions as a tonic substitute sharing two common tones with I, or as the target of a deceptive progression. |
| tonic substitute | A chord, typically vi, that replaces the tonic chord while maintaining harmonic stability; vi shares scale degrees 1 and 3 with I, making the substitution smooth. |
| deceptive progression | A harmonic progression in which V (or V7) moves to vi instead of I, avoiding the expected authentic resolution and creating a sense of interruption. |
| Deceptive cadence | A phrase-ending deceptive progression (V-vi or V-VI); the leading tone resolves up as expected, but the bass moves to scale degree 6 rather than 1. |
| Phrygian Half Cadence | A half cadence using iv6-V in minor keys only; the bass descends by half step from scale degree 4 to scale degree 5, producing a distinctive sound. |
| Mediant | Scale degree 3; the triad built on it (iii in major, III in minor) is rare in 18th-century style; III in minor most often represents the relative major key. |
| Second Inversion | A chord position with the fifth in the bass; in tonal music, second-inversion triads (six-four chords) are restricted to four specific contexts: cadential, neighboring, passing, and arpeggiated. |
| neighboring six-four | A six-four chord that embellishes a single harmony by moving upper voices to their upper neighbors and back while the bass remains stationary; occurs on a weak beat. |
| passing six-four | A six-four chord that harmonizes a bass passing tone in a stepwise scale fragment; occurs on a weak beat; the fifth of the chord is doubled. |
| Perfect Authentic Cadence | V or V7 in root position resolving to I in root position with scale degree 1 in the soprano; the strongest and most conclusive cadence type. |
| Dominant Function | The harmonic role of V and V7, which create strong tension that resolves to tonic; the cadential six-four embellishes this area despite containing tonic-triad pitches. |
The cadential six-four contains the notes of the tonic triad but functions as dominant embellishment. Labeling it as I6/4 with tonic function is incorrect; it belongs to the dominant functional area and must resolve to V.
The cadential six-four must fall on a metrically stronger beat than the V chord that follows. Putting it on a weak beat reverses the metric relationship and is a voice-leading error.
In ii7 or iiø7, the chordal seventh must resolve down by step to the third of V. Leaping the seventh or moving it upward is an error, even when the retention option is used before a cadential six-four.
A deceptive cadence ends on vi, not V. Because the phrase does not close on tonic, students sometimes confuse it with an open ending. Check whether the final chord is V (half cadence) or vi (deceptive cadence).
The diminished triad ii° in minor has a diminished fifth between the bass and the fifth of the chord, which is unstable. Use first inversion (ii°6) instead to place the third in the bass and avoid the dissonant interval against the bass.
The exam regularly asks you to analyze a passage and assign Roman numerals with correct inversion symbols. Unit 5 chords that require precise labeling include ii°6 in minor, ii7 and its inversions, the cadential six-four as V6/4-5/3 rather than I6/4 with tonic function, and vi in a deceptive progression. Misidentifying the functional area of any of these is a common source of lost points.
Four-voice writing tasks test whether you can handle predominant seventh chords (resolving the chordal seventh down by step), place the cadential six-four on a strong beat with correct resolution, and avoid parallel fifths or octaves when moving from predominant to dominant. Error-detection tasks often target the cadential six-four on a weak beat, an unresolved chordal seventh, or ii° in root position in a minor key.
Listening tasks ask you to identify cadence types by ear, including the plagal, Phrygian half, and deceptive cadences introduced in this unit. You may also be asked to identify the functional area of a chord within a heard progression or to recognize the characteristic sound of a cadential six-four resolving to V. Practicing with short musical examples and naming each cadence type before checking is the most direct preparation.
Open the individual guides for Unit 5 when you want a closer review of one topic.
browse guidesPractice free-response reasoning and compare your answer with scoring guidance.
practice FRQsUse unit cheatsheets for a quick visual review after you work through the notes.
open cheatsheetsEstimate your broader AP score goal after you review the course and exam format.
open calculatorAP Music Theory Unit 5 covers chord progressions and predominant function across 7 topics: adding predominant function IV and ii to a melodic phrase, the vi chord, predominant seventh chords, the iii chord, cadences and predominant function, cadential 6/4 chords, and additional 6/4 chords. Together these topics build the harmonic vocabulary you need for analysis and part-writing. See the full topic list at AP Music Theory Unit 5.
The AP Music Theory Unit 5 progress check includes MCQ and FRQ parts drawn from all 7 topics in the unit. Multiple-choice questions test your ability to identify chord progressions, label predominant function chords like IV, ii, and vi, and recognize cadences. FRQ tasks typically ask you to complete or analyze a short harmonic passage using predominant seventh chords and cadential 6/4 chords. Practicing with matched questions at AP Music Theory Unit 5 is one of the best ways to prepare for the progress check format.
AP Music Theory Unit 5 FRQs focus on chord progressions, part-writing, and harmonic analysis, so the best practice targets those skills directly. Expect tasks like writing a four-voice progression that includes predominant function chords (IV, ii, vi), resolving predominant seventh chords correctly, and identifying or completing cadences including cadential 6/4 chords. To practice, write out short progressions from scratch, then check your voice leading for parallel fifths and octaves. Analyzing existing examples from topics 5.1 through 5.7 before writing your own builds the pattern recognition these questions reward. Find practice prompts and study guides at AP Music Theory Unit 5.
The best place to find AP Music Theory Unit 5 practice questions, including multiple-choice and practice test sets, is AP Music Theory Unit 5. That page has resources covering all 7 topics, from identifying chord progressions and predominant function chords to recognizing cadences and 6/4 chords. For MCQ practice, look for questions that ask you to label Roman numerals, spot voice-leading errors, and identify cadence types, since those formats appear most on the actual exam.
Start by making sure you can hear and write the core chord progressions before moving to the harder topics. Here's a concrete plan for Unit 5: 1. **Topics 5.1-5.2** first. Practice adding IV, ii, and vi chords to simple melodic phrases in both major and minor keys. Sing or play each progression so your ear connects to the Roman numerals. 2. **Topic 5.3** next. Drill predominant seventh chords (especially ii7 and ii°7) and their resolutions. Voice-leading errors here are the most common part-writing mistakes. 3. **Topics 5.4-5.5** together. The iii chord is rare, so spend less time on it, but spend real time on cadences and how predominant function sets them up. 4. **Topics 5.6-5.7** last. Cadential 6/4 and additional 6/4 chords have strict doubling and resolution rules. Write them out by hand until the pattern is automatic. After each topic, do a short harmonic analysis of a real piece to see the concept in context. Find practice sets and study guides at AP Music Theory Unit 5.