Harmonic Progressions and Cadences: every key term you need (+ practice quiz)

More AP Music Theory guides

• Scales, Keys, and Intervals
• Triads and Seventh Chords
• Harmonic Function and Voice Leading
• Secondary Function, Modulation, and Form

Cadence

A harmonic and melodic goal that punctuates the end of a phrase, ranging from conclusive to open-ended.

Perfect Authentic Cadence (PAC)

Root-position V (or V7) to root-position I with the tonic in the soprano at arrival; the most conclusive cadence.

Imperfect Authentic Cadence (IAC)

A V–I cadence weakened by inversion, by 3̂ or 5̂ in the soprano, or by vii° substituting for V.

Half Cadence (HC)

A phrase ending on V; open-ended, demanding continuation.

Phrygian Half Cadence

In minor, iv6 moving to V, with the bass descending by half step (6̂→5̂); a hallmark of Baroque slow movements.

Plagal Cadence

IV–I, the 'Amen' cadence; usually follows an authentic cadence as a codetta gesture.

Deceptive Cadence

V resolving to vi (VI in minor) instead of I, evading the expected close and extending the phrase.

Phrase

A complete musical thought, typically four measures in common-practice style, ending with a cadence.

Period

Two phrases in an antecedent–consequent relationship: the first ends inconclusively (usually HC), the second conclusively (usually PAC).

Parallel Period

A period whose two phrases begin with the same or similar material.

Contrasting Period

A period whose consequent begins with different material from the antecedent.

Sentence

A phrase design of presentation (idea stated then repeated) followed by continuation and cadence, often in 2+2+4 proportions.

Cadential 6/4

A tonic 6/4 chord on a strong beat that decorates V: the 6th and 4th above the bass resolve down to the 5th and 3rd; analyzed as part of the dominant.

Passing 6/4

A 6/4 chord whose bass fills a third with stepwise motion, e.g., I–V6/4–I6; metrically weak.

Pedal (Neighbor) 6/4

A 6/4 built over a stationary bass, e.g., I–IV6/4–I; the upper voices move as neighbors while the bass holds.

Arpeggiated 6/4

A 6/4 created when the bass arpeggiates through chord members; common in accompaniment figures.

Harmonic Rhythm

The rate at which chords change; often accelerates approaching a cadence.

Circle-of-Fifths Sequence

A progression of roots falling by fifths (e.g., vi–ii–V–I); the strongest engine of tonal motion.

Sequence

Immediate restatement of a melodic/harmonic pattern at a different pitch level, usually preserved two or three times.

Descending 5–6 Sequence

A sequence alternating 5/3 and 6/3 chords over a stepwise descending pattern, avoiding parallels.

Prolongation

Extending the influence of one harmony through neighboring or passing chords before the function changes.

First-Inversion Substitution

Using a chord in first inversion (e.g., ii6 for ii, V6 for V) to smooth the bass line while preserving function.

Root Motion Norms

Strongest root motions: down a 5th (up a 4th); then down a 3rd; then up a 2nd; each tends toward the dominant.

Tonic Expansion

Opening progressions like I–V6–I6 or I–vii°6–I6 that stretch tonic function across several chords.

Dominant Prolongation

Sustaining dominant tension across chords, as in a half-cadence standing on V or a dominant pedal.

Phrase Group

Three or more phrases that belong together without forming a strict period.

Elision

Overlap where the cadence chord of one phrase simultaneously begins the next phrase.

Codetta

A brief closing extension after the final cadence, often plagal or over a tonic pedal.

Cadential Extension

Lengthening a phrase after (or by delaying) its cadence, e.g., repeating the V–I motion.

Picardy vs. Deceptive Endings

Both alter an expected tonic close: Picardy changes the tonic's quality to major; deceptive replaces the tonic chord entirely with vi/VI.

Voice Exchange

Two voices swapping pitches within a prolonged harmony, e.g., bass and soprano trading 1̂ and 3̂ across I–V6/4–I6.

Lament Bass

A bass descending by step (often chromatically) from tonic to dominant, common in minor-mode ostinatos.

Antecedent

The opening, question-like phrase of a period, ending with a weaker cadence such as a half cadence.

Consequent

The answering phrase of a period, ending more conclusively, normally with a PAC.