Editing Leading tone (section)

== Note ==

=== Seventh scale degree (or lower leading tone) ===
Typically, when people speak of ''the'' leading tone, they mean the seventh scale degree ({{music|scale|7}}) of the major scale, which has a strong affinity for and leads melodically to the [[tonic (music)|tonic]].{{sfn|Benward and Saker|2003|loc=203}} It is sung as ''si'' in [[Solfège#Movable do solfège|movable-do solfège]]. For example, in the F major scale, the leading note is the note E.

: <score sound="1">  {
\override Score.TimeSignature #'stencil = ##f
\relative f' {
  \clef treble \key f \major \time 7/4 f4 g a bes c d \once \override NoteHead.color = #red e f2
} }
</score>

As a [[diatonic function]], the leading tone is the seventh scale degree of any [[diatonic scale]] when the distance between it and the tonic is a single [[semitone]]. In diatonic scales in which there is a [[whole tone]] between the seventh scale degree and the tonic, such as the [[Mixolydian mode]], the seventh degree is called the ''[[subtonic]]''. However, in modes without a leading tone, such as [[Dorian mode|Dorian]] and Mixolydian, a raised seventh is often featured during cadences,{{sfn|Benward and Saker|2009|loc=4}} such as in the [[harmonic minor scale]].

A leading tone outside of the current scale is called a ''[[secondary chords|secondary]] leading tone'', leading to a ''secondary tonic''. It functions to briefly [[tonicization|tonicize]] a scale tone (usually the 5th degree){{sfn|Berry|1987|loc=55}} as part of a [[secondary dominant]] chord. In the second measure of [[Ludwig van Beethoven|Beethoven]]'s ''[[Waldstein Sonata]]'' (shown below), the F{{music|sharp}}'s function as secondary leading tones, which resolve to G in the next measure.{{sfn|Berry|1987|loc=55}}

:<score sound="1" lang="lilypond"> {
#(set-global-staff-size 18)
{ \new PianoStaff <<
  \new Staff <<
  \new Voice \relative c {
    \once\override DynamicLineSpanner.staff-padding = #4
    \clef bass \time 4/4
    \tempo "Allegro con brio" 4 = 176
    \override DynamicLineSpanner.staff-padding = #2.5
    r8\pp <c e> <c e> <c e> <c e> <c e> <c e> <c e>
    <c e> <c e> <c e> <c e> <c e> <c e> <d fis> <d fis>
    <d g>4.( b'16 a) g8 r r4
    \clef treble \grace { cis''8( } d4~)( d16 c b a g4-.) r4
  } 
>>
  \new Staff { \relative c, {
   \clef bass
   c8 <c g'> <c g'> <c g'> <c g'> <c g'> <c g'> <c g'>
   <c g'> <c g'> <c g'> <c g'> <c g'> <c g'> <c a'> <c a'>
   <b g'> <b g'> <b g'> <b g'> <b g'> <b g'> <b g'> <b g'>
   <b g'> <b g'> <b g'> <b g'> <b g'>[ <b g'> <b g'> <b g'>]
  } }
>> } } 
</score>

===Descending, or upper, leading tone===
{{Image frame|content=<score sound="1" override_midi="Escribano - Lamentation, upper leading-tone cadence.mid">
    { 
#(set-global-staff-size 18)
<< \new StaffGroup <<
        \new Staff <<
            \clef treble \time 2/2
            \relative c' {
                \clef treble \time 2/2
                e2 f2~ f4 e d2~ d4 \once \set suggestAccidentals = ##t cis8 b \once \set suggestAccidentals = ##t cis!2 d1\fermata
                }
            >>
        \new Staff <<
            \clef treble \time 2/2
            \new Voice \relative c' {
                r2 a f g a1 a1\fermata
                }
            >>
        \new Staff <<
            \clef bass \time 2/2
            \new Voice \relative c' {
                a1 d, e d\fermata
                }
            >>
        \new Staff <<
            \clef bass \time 2/2
            \new Voice \relative c {
                a1 bes a d\fermata \bar "|."
                }
            >>
    >>
>> }
</score>|width=420|caption=Cadence featuring a descending leading tone (B flat – A in the bass voice) from a well-known 16th-century lamentation, the debate over which was documented in Rome c.1540.{{sfn|Berger|1987|loc=148}}<br />[[File:Escribano - Lamentation, upper leading-tone cadence.mid|thumb|left|155px|Upper-leading tone trill]][[File:Escribano - Lamentation, upper leading-tone cadence diatonic.mid|thumb|155px|Diatonic trill]]}}
By contrast, a descending, or upper, leading tone{{sfn|Berger|1987|loc=148}}{{sfn|Coker|1991|loc=50}} is a leading tone that resolves ''down'', as opposed to the seventh scale degree (a ''lower'' leading tone) which resolves up. The descending, or upper, leading tone usually is a lowered second degree ({{music|flat}}{{music|scale|2}}) resolving to the tonic, but the expression may at times refer to a {{music|flat}}{{music|scale|6}} resolving to the dominant.{{Citation needed|date=April 2020}} In German, the term ''Gegenleitton'' ("counter leading tone") is used by [[Hugo Riemann]] to denote the descending or upper leading-tone ({{music|flat}}{{music|scale|2}}),{{sfn|Riemann|1918|loc=113–114}} but [[Heinrich Schenker]] uses {{lang|de|abwärtssteigenden Leitton}}{{sfn|Schenker|1910||pages=143–145}} ("descending leading tone") to mean the descending diatonic [[supertonic]] ({{music|natural}}{{music|scale|2}}).)

The [[tritone substitution]], chord progression ii–subV–I on C (Dm–Db7–C), results in an upper leading note.

:<score sound="1" lang="lilypond"> { 
\new Staff <<
\new Voice \relative c' {
  \clef treble \key c \major \time 4/4 
  \override NoteColumn.force-hshift = #1 \override NoteHead.color = #red s2 des \override NoteColumn.force-hshift = #0.5 c1
} 
\new Voice \relative c' {
  \clef treble \key c \major \time 4/4 
  <d f a c>2 <f aes ces> <e g c>1 \bar "||"
}
>> }
</score>

=== Analysis ===
According to [[Ernst Kurth]],{{sfn|Kurth|1913|loc=119–736}} the [[major third|major]] and [[minor third]]s contain "latent" tendencies towards the [[perfect fourth]] and whole tone, respectively, and thus establish [[tonality]]. However, [[Carl Dahlhaus]]{{sfn|Dahlhaus|1990|loc=44–47}} contests Kurth's position, holding that this drive is in fact created through or with harmonic function, a root progression in another voice by a whole tone or fifth, or melodically ([[monophony|monophonically]]) by the context of the scale. For example, the leading tone of alternating C chord and F minor chords is either the note E leading to F (if F is tonic), or A{{music|b}} leading to G (if C is tonic).

In works from the 14th- and 15th-century Western tradition, the leading tone is created by the progression from imperfect to perfect consonances, such as a major third to a perfect fifth or minor third to a unison.{{Citation needed|date=November 2018}} The same pitch outside of the imperfect consonance is not a leading tone.

Forte claims that the leading tone is only one example of a more general tendency: the strongest progressions, melodic and harmonic, are by [[Semitone|half step]].{{sfn|Forte|1979|loc=11–2}} He suggests that one play a G major scale and stop on the seventh note (F{{music|#}}) to personally experience the feeling of lack caused by the "particularly strong attraction" of the seventh note to the eighth (F{{music|#}}→G'), thus its name.