CADENCE

in music, formula signifying the end of a phrase or half-phrase, section, or entire composition. The concept of cadence implies broadly acknowledged conventions, especially of a harmonic nature, conveying a sense of relative completion, analogous to the use of punctuation in literature. The term derives from the Latin word cadere (to fall) and originally referred to the stepwise descent of the tenor part, associated with formal endings in certain types of late medieval polyphony. With the emergence of functional harmony in the course of the 17th century, the cadence assumed previously unsuspected structural significance, especially in homophonic music, which literally moved from cadence to cadence. Three principal types evolved in this purely harmonic context: the perfect, or full (final), cadence; the half cadence, or semicadence; and the deceptive cadence. The perfect cadence, in turn, can be either authentic (with the dominant as the penultimate chord, resolving to the tonic) or plagal (with the subdominant as the penultimate chord, resolving to the tonic); only the authentic perfect cadence produces a truly decisive ending. Half cadences occur especially at the midpoint of phrases or periods. They fulfill only half of their cadential obligations since, by coming to rest on the dominant rather than the tonic, they fail to provide full release from previously generated harmonic tensions. In fact, it is the residual tension between the half cadence and the original tonic that gives further impetus to the remainder of the phrase or period, until it settles in a final tonic cadence. Deceptive cadences are akin to half cadences in that they, too, are transitory in nature; in deceptive cadences, however, the dominant chord is followed by a tonic substitute, typically the chord built on the sixth scale degree, also known as the submediant. The ensuing deception merely reinforces the desire for a speedy return to the tonic and its confirmation by a perfect cadence. In monophonic music (consisting of a single line of melody), such as plainchant, certain melodic formulas imply cadence. The melodic styles of a culture frequently prescribe the proper final note of a melody and how to approach it. Certain rhythmic patterns may be recognized as indicators of cadence, as in some Japanese music. Colotomic structure, the systematic use of prescribed instruments at fixed rhythmic intervals, may also signal cadencee.g., in Indonesian gamelanas the recognized pattern approaches its end.