Cadence

In Western musical theory, a cadence (Latin cadentia, 'a falling') is 'a melodic or harmonic configuration that creates a sense of resolution .' 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. An examination of the classical repertory reveals that such a cadence rarely exists. ... Inasmuch as the progression IV–I cannot confirm a tonality (it lacks any leading-tone resolution), it cannot articulate formal closure .... Rather, this progression is normally part of a tonic prolongation serving a variety of formal functions – not, however a cadential one. Most examples of plagal cadences given in textbooks actually represent a postcadential codetta function: that is, the IV–I progression follows an authentic cadence but does not itself create genuine cadential closure.' In Western musical theory, a cadence (Latin cadentia, 'a falling') is 'a melodic or harmonic configuration that creates a sense of resolution .' 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. 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, as at the end of a phrase. Harmonic rhythm plays an important part in determining where a cadence occurs. Cadences are strong indicators of the tonic or central pitch of a passage or piece. Edward Lowinsky proposed that the cadence was the 'cradle of tonality'. In music of the common practice period, cadences are divided into four main types, according to their harmonic progression: authentic (typically perfect authentic or imperfect authentic), half, plagal, and deceptive. Typically, phrases end on authentic or half cadences, and the terms plagal and deceptive refer to motion that avoids or follows a phrase-ending cadence. Each cadence can be described using the Roman numeral system of naming chords. An authentic cadence is a cadence from V to I (i.e. dominant to tonic). A seventh above the root is often added to create V7, and the V is often preceded by a cadential 64 chord. The Harvard Concise Dictionary of Music and Musicians says, 'This cadence is a microcosm of the tonal system, and is the most direct means of establishing a pitch as tonic. It is virtually obligatory as the final structural cadence of a tonal work.' Authentic cadences are generally classified as either perfect or imperfect. The phrase perfect cadence is sometimes used as a synonym for authentic cadence but can also have a more precise meaning depending on the chord voicing. In a perfect authentic cadence (PAC), the chords are in root position – that is, the roots of both chords are in the bass – and the tonic is in the highest voice of the final chord. This is generally considered the strongest type of cadence and often found at structurally defining moments. Music theorist William Caplin writes that the perfect authentic cadence 'achieves complete harmonic and melodic closure.' There are three distinct types of imperfect authentic cadences (IAC): An evaded cadence goes from V42 to I6. Because the seventh must fall step wise, it forces the cadence to resolve to the less stable first inversion chord. To achieve this, a root position V usually changes to a V42 right before resolution, thereby 'evading' the cadence. (See also inverted cadence below.) A half cadence (also called an imperfect cadence or semicadence) is any cadence ending on V, whether preceded by II (V of V), ii, vi, IV, or I—or any other chord. Because it sounds incomplete or suspended, the half cadence is considered a weak cadence that calls for continuation.