a harmonic or melodic formula that occurs at the end of a section in a musical work and imparts a completeness and wholeness. In harmony the distinction is made between full (concluding with the tonic triad) and half cadences (concluding with the dominant or subdominant). In turn, full cadences are subdivided into authentic (tonic is preceded by the dominant) and plagal (tonic is preceded by the subdominant), perfect (tonic appears as last chord, with the tonic note in the soprano, and either the dominant or subdominant preceding it, both in root position) and imperfect (in which the conditions for forming the perfect cadence are not observed). Interrupted cadences replace the tonic in the authentic cadence with another chord. By dividing a musical composition into separate sections, cadences help to establish a definite logical and functional relationship among them.
Cadenza. A cadenza is a virtuoso solo episode in an instrumental concerto; it may be a free fantasia based on the theme of the concerto. The Viennese classical school left the composition or extemporization of cadenzas to the performer. Later composers (beginning with Beethoven), striving for a structural and stylistic compositional unity, wrote their own cadenzas.
IU. N. KHOLOPOV