This cheat sheet explains the four main cadence types used in tonal music: authentic, plagal, half, and deceptive. Cadences help musicians hear where phrases pause, finish, or create surprise. Students need this reference to identify harmonic motion, analyze scores, and write stronger phrase endings.
It is especially useful for theory, composition, and sight-singing practice.
The most important idea is that a cadence is defined by its final chord motion and the sense of closure it creates. Authentic cadences use V to I or V7 to I, plagal cadences use IV to I, half cadences end on V, and deceptive cadences use V to vi in major or V to VI in minor. Strong cadences usually place the tonic in a stable position and often land on a strong beat.
Roman numerals, key awareness, and bass motion are the main tools for recognizing each type.
Key Facts
- An authentic cadence moves from V to I or V7 to I and usually gives the strongest sense of finality.
- A perfect authentic cadence is V to I or V7 to I with both chords in root position and scale degree 1 in the soprano on the final I chord.
- An imperfect authentic cadence is any V to I cadence that is not perfect, such as one with an inverted chord or scale degree 3 or 5 in the soprano.
- A plagal cadence moves from IV to I and often sounds like the word setting of amen in hymns.
- A half cadence ends on V and creates an unfinished sound, often leading the listener to expect more music.
- A deceptive cadence usually moves from V to vi in a major key or V to VI in a minor key, avoiding the expected tonic resolution.
- In a major key, the basic cadence formulas are authentic: V to I, plagal: IV to I, half: any chord to V, and deceptive: V to vi.
- Cadence identification depends on the key, so the same chord names can have different Roman numerals in different keys.
Vocabulary
- Cadence
- A cadence is a harmonic pattern at the end of a phrase that creates a sense of pause, closure, or continuation.
- Authentic Cadence
- An authentic cadence is a phrase ending that moves from the dominant chord to the tonic chord, usually written V to I.
- Plagal Cadence
- A plagal cadence is a phrase ending that moves from the subdominant chord to the tonic chord, written IV to I.
- Half Cadence
- A half cadence is any cadence that ends on the dominant chord, written as any chord to V.
- Deceptive Cadence
- A deceptive cadence is a cadence where V resolves to a chord other than I, most commonly vi in major keys.
- Roman Numeral Analysis
- Roman numeral analysis labels chords by their scale-degree function within a key, such as I for tonic and V for dominant.
Common Mistakes to Avoid
- Calling every V to I cadence perfect is wrong because a perfect authentic cadence must have both chords in root position and scale degree 1 in the soprano.
- Identifying a half cadence as V to I is wrong because a half cadence ends on V and does not resolve to the tonic yet.
- Ignoring the key is wrong because Roman numerals depend on the tonic, so the same chord can function differently in another key.
- Confusing plagal and deceptive cadences is wrong because IV to I is plagal, while V to vi or V to VI avoids the expected tonic resolution.
- Looking only at the melody is unreliable because cadence type is defined mainly by the chord progression and harmonic function at the phrase ending.
Practice Questions
- 1 In C major, identify the cadence type for the progression G to C and write the Roman numerals.
- 2 In G major, identify the cadence type for the progression D to Em and write the Roman numerals.
- 3 In F major, identify the cadence type for the progression Bb to F and write the Roman numerals.
- 4 Explain why a phrase ending on V feels less final than a phrase ending with V to I.