Editing Cadence (section)

===Authentic cadence===<!--[[Perfect authentic cadence]] redirects directly here.-->
{{Image frame|content=<score sound="1" override_midi="Beethoven - Piano Sonata, Op. 13 perfect authentic cadence.mid">
    {
      \override Score.SpacingSpanner.strict-note-spacing = ##t
  \set Score.proportionalNotationDuration = #(ly:make-moment 1/8)
      \new PianoStaff <<
        \new Staff <<
            \relative c'' {
                \clef treble \key c \minor \time 4/4
                c4-. d-.(\f\trill \grace {c16 d} es4-.) <b d b'>-. <c es c'>
                }
            >>
        \new Staff <<
            \relative c' {
                \clef bass \key c \minor \time 4/4
                c4-. <g b>-. <c, c'>-. <g g'>-. <c, c'>
                }
            >>
    >> }
</score>|width=300|caption=The final two chords represent a perfect authentic cadence; from [[Beethoven]]'s [[Piano Sonata No. 8 (Beethoven)|Piano Sonata No. 8]], mvmt. III, mm. 16–17.<ref>{{cite book|last=White|first=John D.|year=1976|title=The Analysis of Music|page=34|publisher=Prentice-Hall |isbn=0-13-033233-X}}.</ref>}}An authentic cadence is a cadence from the [[Dominant (music)|dominant]] chord (V) to the [[root (chord)|root chord]] (I). During the dominant chord, a [[seventh (interval)|seventh]] above the dominant may be added to create a [[dominant seventh chord]] (V<sup>7</sup>); the dominant chord may also be preceded by a [[Cadential six-four|cadential {{music|64 chord}} 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."<ref name="Randel" /> 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 (music)|voicing]].

====Perfect authentic cadence====
In a perfect authentic cadence (PAC), the chords are in [[root position]] – that is, the [[root (chord)|roots]] of both chords are in the bass – and the [[Tonic (music)|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.<ref>Thomas Benjamin, Johann Sebastian Bach (2003). ''The Craft of Tonal Counterpoint'', p. 284. {{ISBN|0-415-94391-4}}.</ref> Music theorist [[William Caplin]] writes that the perfect authentic cadence "achieves complete harmonic and melodic closure."<ref>[[William Caplin|Caplin, William E]]. (2000). ''Classical Form: A Theory of Formal Functions for the Instrumental Music of Haydn, Mozart, and Beethoven'', p. 51. {{ISBN|0-19-514399-X}}.</ref>
{{block indent|<score sound="1">
   \new PianoStaff <<
      \new Staff <<
         \new Voice \relative c'' {
             \stemUp \clef treble \key c \major \time 4/4
             b1 c
             }
         \new Voice \relative c'' {
             \stemDown
              g1 g
              }
            >>
     \new Staff <<
         \new Voice \relative c' {
             \stemUp \clef bass \key c \major \time 4/4
             d1 e
             }
         \new Voice \relative c' {
             \stemDown
             g1 c, \bar "||"
             }
         >>
    >>
</score>}}

====Imperfect authentic cadence====

There are three types of imperfect authentic cadences (IAC):<ref name="K&P 246">{{Cite book|title=Tonal Harmony|last1=Kostka|first1=Stefan|author1-link=Stefan Kostka|last2=Payne|first2=Dorothy|date=2004|publisher=McGraw-Hill|isbn=0072852607|edition=5th|location=Boston|pages=148–149|oclc=51613969}}</ref>

*''Root position IAC'' (shown below): Similar to a perfect authentic cadence, but the highest voice is not the tonic.
{{block indent|<score sound="1">
   \new PianoStaff <<
      \new Staff <<
         \new Voice \relative c'' {
             \stemUp \clef treble \key c \major \time 4/4
             d1 e
             }
         \new Voice \relative c'' {
             \stemDown
              g1 g
              }
            >>
     \new Staff <<
         \new Voice \relative c' {
             \stemUp \clef bass \key c \major \time 4/4
             b1 c
             }
         \new Voice \relative c' {
             \stemDown
             g1 c, \bar "||"
             }
         >>
    >>
</score>}}
*''Inverted IAC'': Similar to a perfect authentic cadence, but one or both chords are [[Inverted chord|inverted]].
*''[[Leading-tone]] IAC'': The penultimate (V) chord is replaced with a chord based on the leading-tone (vii<sup>o</sup> chord).

=====Evaded cadence=====

An evaded cadence (a subtype of the inverted IAC) moves from a dominant seventh [[third inversion]] chord (V{{su|b=2|p=4}}) to a [[first inversion]] tonic chord (I{{su|p=6}}).<ref>Darcy and Hepokoski (2006). ''Elements of Sonata Theory: Norms, Types, and Deformations in the Late-Eighteenth-Century Sonata'', p.. {{ISBN|0-19-514640-9}}. "the unexpected motion of a cadential dominant chord to a I<sup>6</sup> (instead of the typically cadential I)"</ref> Because the seventh of the dominant chord must fall stepwise to the third of the tonic chord, it forces the cadence to resolve to the less stable first inversion chord. To achieve this, a root position V usually changes to a V{{su|b=2|p=4}} right before resolution, thereby "evading" the root-position I chord that would usually follow a root-position V. (See also [[#Inverted cadence|inverted cadence]] below.)

{{block indent|<score sound="1">
   \new PianoStaff <<
      \new Staff <<
         \new Voice \relative c'' {
             \stemUp \clef treble \key c \major \time 4/4
             b1 c1
             }
         \new Voice \relative c'' {
             \stemDown
              g1 g1
              }
            >>
     \new Staff <<
         \new Voice \relative c' {
             \stemUp \clef bass \key c \major \time 4/4
             d1 c1
             }
         \new Voice \relative c' {
             \stemDown
             g2 f e1 \bar "||"
             }
         >>
    >>
</score>}}