1. Mr. Jackson AP Music Theory

2.  A cadence is the harmonic, melodic, and rhythmic conclusion to a phrase. It also helps to establish the tonal center. It is the proof we need to confidently determine what key we are in.  Think of cadences as musical punctuation. Let’s construct some sentences:  Sentence 1: Construct a sentence that is thorough and ends with a predictable, complete thought.  Sentence 2: Construct a sentence that you think will end predictable, but leaves you wondering…  Sentence 3: Construct a sentence that is incomplete and leaves you hanging…

3.  Composers have always had an intuitive sense of how music “ends” or concludes.  Early cadences were simple, quaint, and to some – unfulfilling.  Prior to the baroque period and the establishment of functional harmony, cadences were considered simply a manipulation of melodic lines that converged or diverged to a point of rest, usually the final (the first degree of a mode). Here are some early types of cadences:

4.  The baroque period brought about the familiar cadence types:  The standard cadences (authentic, half, plagal, and deceptive) continued with little change from the baroque period throughout the classical period.

5.  Authentic Cadence – The most common phrase-ending chord progression uses the dominant chord (V) to set up the tension and the tonic (I or i) for the release.  Perfect Authentic (PAC) – Requires both dominant and tonic chords to be in ROOT POSITION. Also, the SOPRANO VOICE must have tonic!  Imperfect Authentic (IAC) – Weaker authentic (V – I) cadence that has either chord INVERTED, or has a chord member other than the root in the soprano of the tonic chord. Could also contain the vii o or vii o6 to tonic.  Plagal Cadence (PC) – Slightly weaker progression using subdominant to tonic (IV to I) Nicknamed the “Amen Cadence,” and is traditionally used when singing “Amen” at the end of hymns.  Deceptive Cadence (DC) – An ending progression where the dominant chord is unexpectedly resolved to the submediant instead of the tonic. (V to vi) All other chord tones resolve correct, except the bass.  Half Cadence (HC) – Ends on the dominant (V). It’s unresolved tension is used in the middle of a melody, an inconclusive cadence that typically ends on a root position V. This cadence acts like a “comma” in a sentence and must be followed by another phrase that completes the musical thought.  Phrygian Half Cadence (PHC) – A specific kind of half cadence that occurs in harmonic minor. (iv 6 to V) The descending bass line (Leto Sol) is approached from above by a half step and is characteristic of the Phrygian mode with its half step.

9. The IAC example could also include inversions.

15. CadenceProgression Half (HC) ANY V, V 7 Phrygian Half (PHC) iv 6 V, V 7 Perfect Authentic (PAC) V, V 7 I TONIC IN SOP Imperfect Authentic (IAC) vii o6, vii  7,V 6, V I Deceptive Cadence (DC) V, v VI, vi Plagal Cadence (PC) IV, iv I, i