Music 160A: Cadences

• authentic
• half

There are two varieties of authentic cadences, both of which signal a harmonic close by means of a dominant-tonic progression. They differ in the type of melodic close:

• perfect: V-I where the voice leading indicates a conclusive melodic ending
• imperfect: V-I where the voice leading indicates a relatively inconclusive melodic ending

Composers deliberately shape harmonic and melodic attributes of authentic cadences to give them more or less closural strength. Depending on that strength, cadences make their associated musical units sound more conclusive or less conclusive.

Half cadences end on a dominant chord and thus do not signal a harmonic close; on the contrary, they indicate that the current musical unit is incomplete and still under way toward conclusion. Half cadences do, however, give a sense of a provisional melodic close. In short, half cadences are interim endings on the way to definitive ones.

Details: Authentic Cadences
Perfect Authentic Cadence (PAC)
Perfect authentic cadences require two things:

1. the melody over the V-I progression must move stepwise to the tonic note (either 2-1 or 7-8)
2. both the dominant and tonic chords must be in root position

The stepwise melodic line together with the decisive root-to-root leap in the bass (either a descending fifth or an ascending fourth) give this cadence a decisively (i.e. "perfectly") closed feeling.

Occasionally, the melody note preceding the tonic in a PAC may have a small embellishment. For instance, an escape tone may appear in between scale degree 2 and 1: 2-(3)-1 [as in A-(B)-G in the key of G major]. (Example 1 Audio...). The embellishment may even be slightly longer, as in the following scalar decoration: 2-(3-4-5)-1. (Example 2 Audio...) In both of these cases, and in other similar ones, the main melodic tone preceding the tonic is 2, and the intervening notes are decorative (often fast notes), not cadentially structural.

In all cases, with or without embellishment following 2, the melody arrives on scale degree 1 either at the same time as the root of the tonic chord arrives in the bass, or perhaps momentarily delayed by a suspension or appoggiatura. (Example 3 Audio...).

Imperfect Authentic Cadence (IAC)
An authentic cadence is "imperfected" (that is, made less conclusive than a PAC) when one or both of the requirements for a PAC are not met:

1. the melody does not end on scale degree 1 when the tonic chord arrives
2. the tonic chord may be inverted

Special Note:
In many IAC's, the bass may meet the requirements for a PAC (both V and I appear in root position) and the melody, after arriving on scale degree 3 over tonic, may then wend its way toward 1, as in 3(-4-3-2-1). (Example 4 Audio...) The notes following 3 in this case are embellishments, and the eventual arrival on 1 does not make the cadence a PAC[2]. This is an embellished IAC, not an embellished PAC. Following are some examples of imperfect authentic cadences that resemble the model in Example 4.

Bach, French Suite 5, Gavotte, mm. 1-4 (Audio...)
Händel, Keyboard Suite 14, Courante, mm. 1-4 (Audio...)
Bach, French Suite 5, Sarabande, mm. 1-8 (see mm. 7-8) (Audio...)


The following few examples of imperfect cadences include an escape tone as part of the melodic embellishment that leads from scale degree 3 down to 1.

Bach, English Suite 1, Bourree 1, mm. 1-4 (Audio...)
Bach, English Suite 2, Bourree 2, mm. 1-4 (Audio...)
Bach, French Suite 5, Bourree 1, mm. 1-4 (Audio...)

Details: Half Cadence (HC)
The half cadence is less well defined than the authentic types. The only requirement is harmonic, namely that the phrase end on a dominant chord (or dominant seventh). Generally, the chord is in root position, but it need not be. Further, the melody often closes on scale degree 2 or 7 (5th or 3rd of V), both of which strongly imply a subsequent phrase that ends on 1, which melodically resolves the previous phrase ending on 2 or 7. (Example 5, Audio...; Example 6, Audio...) However, a half cadence could just as well end on scale degree 5 (root of V), or even on 4 (7th of V7)!

The important point to remember is that not every instance of a dominant chord defines a half cadence. The chord must stand at the end of a phrase, and must sound like the goal of that phrase. In the eighteenth and early nineteenth-century repertoire, such a phrase is commonly followed by a melodically similar companion phrase that ends with an authentic cadence, either perfect or imperfect.