What is a Cadence?
A cadence is a moment of melodic and harmonic closure created by the use of a conventional harmonic formula together with a melodic resting point. The conventional harmonic formula that leads to the cadence is called a cadential progression. The single element shared by all variations of the cadential harmonic formula is a D5ˆ chord occuring in a metrically strong position. This D5ˆ is called the cadential dominant.
Analyzing Cadential Progressions
Cadential progressions have three stages, although sometimes either stage one or stage two is missing. The first stage is an initial tonic: a I6 (T3ˆ), or sometimes a substitute harmony (any T1ˆ, T3ˆ, or T6ˆ), usually occuring on a strong beat. (If the phrase begins with an anacrusis or pickup, then the initial tonic can occur on the weak-beat pickup.)
The second stage contains one or more structural subdominant chords (also known as pre-dominants, the most common being ii6).
The third stage is the cadential dominant, a D5ˆ on a strong beat. The cadential dominant can have weaker metrical placement than the final tonic’s (if a final tonic exists), but it must have metrical strength similar to or greater than the structural subdominant or initial tonic that immediately precedes it. Note that only a D5ˆ can function as a cadential dominant, while D7ˆ and D2ˆ cannot.
Cadence Types
The Perfect Cadence
We can identify the specific cadence type by examining the degree of closure achieved in the melody and the harmony. The greatest possible degree of closure occurs when the melody comes to rest on Do (1ˆ) above a root position I chord (T1ˆ). When this occurs as the resolution to the cadential dominant, it is a perfect cadence. We shall label perfect cadences using their conventional name: Perfect Authentic Cadence, or PAC.
The Imperfect Cadence
All other cadence types lack some degree of closure when compared with the perfect cadence. If only the melodic closure is lacking, it is an imperfect cadence. Most commonly in an imperfect cadence, the melody comes to rest on Mi (3ˆ). The imperfect cadence must have complete closure in every other regard, however, including both a D5ˆ cadential dominant and a T1ˆ root-position final tonic.
Older cadence taxonomies consider any dominant to tonic progression other than the perfect cadence as an imperfect authentic cadence. Our definition of imperfect cadence is restricted to melodic disruptions of the perfect cadence. We shall discuss cadences that subvert harmonic closure of the perfect cadence later. Only use the label Imperfect Authentic Cadence (IAC) for cadences lacking only in full melodic closure to Do (1ˆ).
The Half Cadence
Sometimes the strong-beat arrival of the cadential dominant is the phrase’s goal rather than arrival on a final tonic. In this case, neither the melody nor the harmony achieve their full closure on Do 1ˆ. A cadence that ends on the cadential dominant is a half cadence or semicadence (HC). In a half cadence, most frequently the melody comes to rest on Re 2ˆ over the cadential D5ˆ, but Ti 7ˆ is also seen frequently, and 5ˆ is also possible in some contexts. One might think that this failure to reach both melodic and harmonic closure would give the music a sense of being interrupted before the D5ˆ can resolve. Instead, the D5ˆ is heard as the harmonic goal of the phrase and becomes more like a tentative partial closure.
Half cadences frequently extend the strong-beat arrival of the D5ˆ cadential dominant, either onto a following weak beat, or into further measures of dominant pedal point. When either of these occurs, the initiating strong-beat cadential dominant is often a cadential six-four chord or a V chord with a 4–3 suspension. When this post-cadential dominant pedal point extends into multiple measures, music theorists like to call it “standing on the dominant”. Standing on the dominant is an important marker of significant formal events in Classical-style music.
The Deceptive Cadence
Perfect, imperfect, and half cadences are all formal cadences that can provide closure to a musical phrase, theme, or section. Deceptive, evaded, and abandoned cadences, however, all lack the closure necessary for the phrase, theme, or section to be complete. They occur where a cadential progression creates the expectation for a formal cadence, but they fail to achieve a proper resolution of D5ˆ cadential dominant to T1ˆ final tonic. Their disruption of the expected cadential closure requires more music after them in order to generate a legitimate cadence.
The deceptive, evaded, and abandoned cadences all interrupt a developing authentic cadential progression with an unexpected denial of closure. The deceptive cadence (DC) resembles a perfect cadence up to the arrival of the final tonic, replacing it with some kind of surprising melodic or harmonic substitution. The most common replacement for the expected final tonic is a vi (T6ˆ) chord. Other common final tonic substitutes include I6, vii°6/V, and V7/IV.
While most Deceptive Cadences have an unexpected harmonic deviation at the moment when the listener expects the final tonic, sometimes even a melodic deviation can create a Deceptive Cadence. Although a V resolving to I with Mi 3ˆ in the melody is usually an Imperfect Cadence, music that sets up the conditions for a Perfect Cadence and then delivers an Imperfect Cadence instead can also be called Deceptive.
The Evaded Cadence
The Evaded Cadence (EC) resembles a Perfect Cadence through the cadential dominant. While a Deceptive Cadence does a bait-and-switch of either the final tonic or melodic closure, the Evaded Cadence breaks off after the cadential dominant and restarts the cadential progression. The main difference between the Deceptive Cadence and the Evaded Cadence is whether the chord after the cadential dominant sounds like it ends the cadential progression or begins a new one.
In the Deceptive Cadence, the suprise harmonic or melodic substitution groups with the preceding cadential progression. Any renewed attempt at closure begins after the unexpected chord. In the Evaded Cadence, however, the second attempt at closure begins instead of the final tonic. This effectively groups the substitute chord with the new cadential progression instead. There are many possible substitutes for final tonic in a Deceptive Cadence, but in an Evaded Cadence the chord that follows the cadential dominant is usually a I6 chord, or whatever chord began the original cadential progression.
The Abandoned Cadence
The abandoned cadence (AC) diverges from expectations much earlier in the authentic cadential progression than deceptive or evaded cadences. Like the deceptive and evaded cadences, an abandoned cadence begins with a perfect cadence formula. But an abandoned cadence either subverts the cadential dominant with a dominant-functioning chord other than D5ˆ on a strong beat, or leaves the cadential dominant out entirely. In either case, a tonic or tonic substitute chord usually appears after the “failed” cadential dominant.
The Passo Indietro and the Comma
An abandoned cadence’s two most common terminating progressions are V42 to I6, called a passo indietro (or retreating cadence), and V6 or V65 to I, called a comma. These two harmonic gestures also tend to occur by themselves, without the preceding perfect cadence formula. In this case, they act as weak cadence-like moments within a theme or phrase. Do not consider these to be cadences, since they lack even an incomplete cadential progression. They are nevertheless useful ways to end an initial tonic prolongation. Use these if full melodic closure ends a tonic zone, or if a cadence is due but not wanted. They are also useful substitutes for a sequential progression between the initial tonic prolongation and cadential progression of a theme. Because these ending gestures do not qualify as formal cadences, we shall call these clausulas, Latin for “small ending”.
Codettas and Closing Sections
If the a perfect cadence’s final tonic is extended using a final tonic prolongation, this is called a codetta. Codettas can be repetitions of the perfect cadence, plagal extensions, or short prolongational progressions, sometimes over a pedal point.
Often a piece will string many codettas together into a passage that rivals the length of a theme or section. Multiple codettas in a row make a closing section. Codettas and closing sections have certain characteristics that set them apart from other types of music. They are nearly always prolongational progressions, often feature repetitive material and melodic flourishes, and often tonicize the subdominant.