In Western musical theory a cadence (Latin cadentia, "a falling") is a particular series of intervals (a caesura) or chords that ends a phrase, section, or piece of music. Cadences give phrases a distinctive ending, that can, for example, indicate to the listener whether the piece is to be continued or concluded. An analogy can be made with punctuation, with some weaker cadences acting as commas, indicating a pause or momentary rest, while a stronger cadence will then act as the period, indicating the end of the phrase or musical sentence. Cadences are called "weak" or "strong" the more or less final the sensation they create, with the perfect authentic cadence being the strongest type.

In music of the common practice period, there are four main types of cadences: authentic, plagal, half, and deceptive. Each of these types can be further distinguished as perfect or imperfect. Each cadence can be described using the roman numeral system of naming triads (see chord):

• Authentic cadence: V to I. The phrase perfect cadence is sometimes used as a synonym for authentic cadence, but can also have a more precise meaning:
  • Perfect authentic cadences: V to I, the chords must be in root position, that is the root of the chords must be in the bass, and the root of I must be in the highest voice also
  • Imperfect authentic cadences: V to I, one or more of the chords are inverted or not in root position or the root of the I is not in the highest voice
• Half (or imperfect) cadence: any chord (frequently I or IV) to V
• Plagal sequence: IV to I, known as the "Amen cadence"
• Deceptive (or interrupted) cadence: V to any chord except I (typically vi)

It should be noted that these chord sequences do not necessarily constitute a cadence — there must be a sense of closure, as at the end of a phrase. Early music cadences, for instance, are different and more varied, being based upon dyads.

"Forbidden" progressions may be reconsidered as allowable progressions. For example, I-V-IV-I, which is disallowed owing to the V-IV motion, may be considered a doubled plagal cadence: I-IV/V-V-IV-I.

Edward Lowinsky considered the cadence the "cradle of tonality." (Judd, 1998)

Clausulas

A clausula is a dyadic or intervallic, rather than chordal or harmonic, cadence. It requires at least two voices in contrary motion. According to Carl Dahlhaus (1990), "as late at the 13th century the half step was experienced as a problematic interval not easily understood, as the irrational remainder between the perfect fourth and the ditone [4/3 / (9/8)2 = 256/243!]." In a melodic half step, no "tendency was preceived of the lower tone toward the upper, or of the upper toward the lower. The second tone was not taken to be the 'goal' of the first. Instead, the half step was avoided in clausulas because it lacked clarity as an interval." Beginning in the 13th century cadences begin to require motion in one voice by half step and the other a whole step in contrary motion.

Source

• Judd, Cristle Collins (1998). "Introduction:Analyzing Early Music", Tonal Structures of Early Music (ed. Judd). New York: Garland Publishing. ISBN 0815323883.

See also

• Tierce de Picardie