Cadences
Cadences
Cadences
Every phrase ends in a cadence consisting of two chords, the second of which (the cadence-chord) occurs on an accented beat.
A cadence is never preceded by either of the two chords involved in that cadence (with the exception of the I64 - V - I progression).
Perfect Cadences
Perfect cadences represent the greatest degree of melodic and harmonic closure, analogous to full stops. The tonic triad is preceded by dominant
harmony, with both chords in root position and a stepwise motion to the tonic (2 - 1 or 7 - 1) in the soprano.
The only other place in a phrase that the progression V - I (with both chords in root position) can occur from an unaccented to an accented beat, is at
the beginning of the phrase.
Imperfect Cadences
Imperfect cadences represent a lesser degree of melodic closure than perfect cadences. The tonic triad is preceded by dominant harmony, with both
chords in root position and a skip or stepwise motion to the mediant (5 - 3, 4 - 3 or 2 - 3) or repeated note (5 - 5) in the soprano.
Plagal Cadences
Half cadences are used to terminate antecedent phrases, analogous to semi-colons. The root-position dominant triad is preceded by any other chord
(except iii) in root-position or inversion and the soprano may close on any note of the dominant triad by skip, stepwise motion or repeated note.
Deceptive Cadences
Deceptive cadences are not cadences, but a way of extending phrases, analogous to commas. Root-position dominant harmony resolves to vi or IV6.