Cadences
Tell the authentic, plagal, half and deceptive cadences apart and hear how each ends a phrase.
How a phrase ends
A cadence is the chords at the end of a phrase. It works like punctuation.
- Authentic (D → T): the most decisive ending, a "full stop".
- Plagal (S → T): also an ending, but soft, without the tension of the dominant. It is known as the "amen cadence".
Both end on the tonic, so both complete the thought.
An authentic cadence in C major: D → T
A plagal cadence: S → T
Practice: A cadence in D major
Practice: A cadence in F major
Open endings
- A half cadence stops on the dominant. The phrase sounds like a question or a comma and asks to go on.
- A deceptive cadence tricks the ear: after the dominant, instead of the tonic, comes the triad on degree VI. The thought turns aside, and the music carries on.
In the deceptive cadence the triad on VI is minor and shares two notes with the tonic, which is why the substitution sounds natural.
A half cadence: T → D
A deceptive cadence: D → vi
Judge a cadence by its last chord. The tonic: authentic or plagal (look at the one before: D or S). The dominant: half. Degree VI: deceptive.