Unit 5: Harmony and Voice Leading II: Chord Progressions and Predominant Function

Functional harmony

A system in common-practice tonal music that explains chord roles (tonic, predominant, dominant) and typical chord-to-chord connections.

Common-practice tonal music

The tonal style most associated with AP Music Theory part-writing/analysis, where chord progressions follow established patterns rather than random order.

Harmonic function

The job a chord performs in a key (stability as tonic, preparation as predominant, or tension as dominant).

Tonic function (T)

Harmony that confirms the key and feels stable or at rest (“home”).

Predominant function (PD)

Harmony that creates motion away from tonic and prepares the arrival of dominant (also called pre-dominant).

Dominant function (D)

Harmony with the strongest tension that points back to tonic and demands resolution.

T → PD → D → T model

A common large-scale phrase backbone: start at tonic, move to predominant, intensify with dominant, and resolve back to tonic.

Root motion

The intervallic movement between chord roots; certain root motions project stronger direction in tonal progressions.

Descending fifth / ascending fourth motion

Strong, goal-directed root motion aligned with the circle of fifths (e.g., ii → V; IV → vii°).

Stepwise root motion

Root movement by step (up/down a second) that can work well when supported by good voice leading and common tones.

Circle of fifths

A tonal pattern relating keys/chords by perfect fifths; progressions moving by descending fifths often sound especially directed.

Harmonic syntax

The “grammar” of tonal harmony—expected functional orderings like PD → D and D → T.

Retrogression

A stylistically atypical backward functional motion (e.g., D → PD) that can weaken tonal direction unless clearly justified.

Cadence

A harmonic-structural arrival that closes or pauses a phrase, typically involving dominant-to-tonic behavior (or other cadential gestures).

Authentic cadence

A cadence type associated with strong closure built around dominant resolving to tonic (V or V7 resolving to I/i).

Half cadence

A phrase ending that stops on the dominant, creating a sense of pause and expectation rather than final resolution.

Plagal motion

The progression IV → I (or iv → i), often heard as an “Amen”-like cadential gesture rather than an authentic cadence.

“Amen” sound

A common nickname for plagal motion (IV → I), frequently used as a closing gesture.

Tonic zone

The phrase area that establishes the key using tonic harmonies (often I and sometimes I6 with prolongation).

Predominant zone

The phrase area that prepares the dominant, typically using ii, ii6, IV, iv, ii°6, etc.

Dominant zone

The phrase area that heightens tension with V, V7, and cadential expansions before resolving to tonic.

Tonic prolongation

Extending the tonic area (staying in the tonic zone) without clearly moving into predominant preparation.

Supertonic chord (ii)

A diatonic chord built on scale degree 2; a primary predominant harmony (minor in major keys, diminished in minor keys).

Subdominant chord (IV)

The chord built on scale degree 4; in major it is a major triad and commonly functions as predominant.

ii° (diminished supertonic)

The supertonic triad in minor, built on scale degree 2; diminished in the natural minor collection and typically used as predominant.

iv (minor subdominant)

The subdominant triad in minor (built on scale degree 4); a common predominant that leads to V in minor-key phrases.

ii–V–I progression

A common functional pattern: predominant (ii) to dominant (V or V7) to tonic (I), especially typical and easy to hear.

V7 (dominant seventh chord)

A dominant-function chord with an added chordal seventh that intensifies pull to tonic and requires specific resolutions.

Common tone

A pitch shared by consecutive chords that can often be held, creating smoother voice leading (e.g., ii to V7 can share tones).

Tendency tone

A scale degree with a strong, typical resolution tendency (especially in dominant harmony), crucial for convincing cadences.

Leading tone (scale degree 7)

The note a semitone below tonic that strongly tends to resolve up to scale degree 1, especially prominent in dominant harmony.

Chordal seventh

The seventh above the root in a seventh chord (like V7) that typically must resolve down by step in proper voice leading.

Resolution (in harmony)

The expected motion from tension to stability, especially dominant (and its tendency tones) resolving to tonic.

SATB part-writing

Four-voice chorale-style writing (soprano, alto, tenor, bass) assessed on AP for correct harmony and voice leading.

Voice leading

How individual melodic lines move from chord to chord (smooth lines, correct resolutions, and avoidance of parallels).

Parallel fifths

A forbidden voice-leading error where two voices move in similar motion from one perfect fifth to another perfect fifth.

Parallel octaves

A forbidden voice-leading error where two voices move in similar motion from one octave to another octave, weakening independence.

Spacing guideline (upper voices)

A common SATB norm: keep soprano–alto and alto–tenor within an octave (bass may be farther).

Figured bass

A notation system indicating chord inversion/intervals above the bass (e.g., 6 for first inversion, 6/4 for second).

Root position (5/3)

A triad with its root in the bass (often unlabeled as 5/3 in Roman numeral contexts).

First inversion (6)

A triad with its third in the bass; commonly used to smooth bass lines (especially with predominant chords like ii6).

Second inversion (6/4)

A triad with its fifth in the bass; treated as less stable and often considered embellishing/context-dependent in common-practice style.

ii6

A supertonic triad in first inversion (third in the bass); a very common, smooth predominant before V or V7.

ii°6

A diminished supertonic triad in first inversion in minor; a standard predominant choice that improves control and voice leading.

Doubling

In SATB, repeating a chord tone to supply four voices; the choice affects stability and ease of correct resolution.

Doubling the leading tone (avoid)

A common style guideline: avoid doubling scale degree 7 because it strongly wants to resolve and is easy to mishandle.

Doubling the third in diminished triads

A common safer practice for diminished triads (like ii°): in first inversion, doubling the third (the bass note) reduces instability.

Cadential 6/4

A 6/4 sonority near a cadence typically understood as part of dominant expansion rather than a stable, independent predominant chord.

Harmonic sequence

A repeating harmonic pattern transposed to different pitch levels, creating predictable forward momentum.

Circle-of-fifths sequence

A sequence with roots moving by descending fifths/ascending fourths (e.g., I → IV → vii° → iii → vi → ii → V → I), often building momentum toward cadence.