Cadences

Why we need Cadences A cadence is where the music reaches some kind of goal – often accompanied by a rhythmic pause. The music between cadences is called a phrase. Cadences separate phrases and act very much like grammatical periods while musical phrases are like grammatical sentences. These devices are important in musical structure because they divide the music into smaller, bite- sized, manageable pieces.

Why we need Cadences A harmonic cadence is a progression of (at least) two chords that concludes a phrase, section, or piece of music. A rhythmic cadence is a characteristic rhythmic pattern that indicates the end of a phrase. A cadence is labeled more or less "weak" or "strong" depending on its sense of finality.

Why we need Cadences While cadences are usually classified by specific chord or melodic progressions, the use of such progressions does not necessarily constitute a cadence—there must be a sense of closure. Harmonic rhythm plays an important part in determining where a cadence occurs.

Perfect Cadence Dominant (V, V⁷) to Tonic (I or i) harmonic motion is the strongest and most common type of cadence because it returns (re-stabilizes) the music back to the home (tonic) chord. Subtle degrees of strength can be determined by the inversion of the chords (root position is the strongest) or the melodic scale degree (the root is the strongest). V/V⁷ /vii ˚ → I/i A seventh is sometimes added to the dominant chord (V7), but the seventh must resolve to the third of the tonic.

Perfect Cadence An example of an Authentic Perfect Cadence in C major:

Plagal Cadence Subdominant (IV or iv) to Tonic (I or i) harmonic motion: strong because it goes to the tonic, but not as strong as the authentic cadence because the motion is "less progressive" (down by a 4th) and because there is no leading tone in the IV/iv chord. IV/iv → I/i Although the cadence ends on the tonic chord, the subdominant is less powerful than the dominant as a chord preceding the tonic. It is sometimes called the "Amen" cadence, as the cadence would often appear in hymns to the words 'amen'.

Plagal Cadence An example of a plagal cadence (IV - I) in C major:

Imperfect (half) Cadence An imperfect/half cadence is a cadence which leads to the dominant chord, but doesn't have a finished feel. The chord that precedes the dominant chord is often a choice of: I (tonic); II (Supertonic); IV (Subdominant) or VI (SubMediant), although other chords do occur.

Imperfect Cadence An example of an Imperfect/Half Cadence (I - V) in C major:

Imperfect Cadence There is a specific type of imperfect/half cadence known as the 'Phrygian cadence'. The descending semitone in the base resembles that of the flattened supertonic - tonic movement of the phrygian mode. The Cadence happens in minor keys, with the progression iv b - V.

Imperfect Cadence An example of a Phrygian Cadence (iv b - V) in C minor:

Deceptive Cadence An interrupted/deceptive cadence is a chord progression from the dominant to any chord other than the tonic. When the dominant is heard, a perfect/authentic cadence (V-I) is expected, so the next chord interrupts the music or deceives the listener. The Interrupted/deceptive cadence is thought of as a weak cadence harmonically, but can have a dramatic effect.

Deceptive Cadence An example of an interrupted/deceptive cadence in C major (V - vi):

The Cadential 6/4 The cadential 6/4 ('six - four') is the name given to a common three chord cadence. Third inversion chords are labelled in figured bass as '6/4' chords, hence the name 'cadential 6/4'. It is thought to be a function of the dominant chord. Hence, some people label the progression 'V 6/4 - 5/3 I'.

The Cadential 6/4 An example of a cadential 6/4 in C major: I6/4 – V I