Leading tone

A leading-tone chord is a triad built on the seventh scale degree in major and the raised seventh-scale-degree in minor. The quality of the leading-tone triad is diminished in both major and minor keys. For example, in both C major and C minor, it is a B diminished triad (though it is usually written in first inversion, as described below). According to John Bunyan Herbert, (who uses the term "subtonic", which later came to usually refer to a seventh scale degree pitched a whole tone below the tonic note), Function The leading-tone triad is used in several functions. It is commonly used as a passing chord between a root position tonic triad and a first inversion tonic triad: that is, "In addition to its basic function of passing between I and I, VII has another important function: it can form a neighboring chord to I or I." In that instance, the leading-tone triad prolongs tonic through neighbor and passing motion. The example below shows two measures from the fourth movement of Beethoven's Piano Sonata No. 3 in C major, Op. 2 in which a leading-tone triad functions as a passing chord between I and I. : \new PianoStaff 4. } >> \new Staff 4. } >> >> The leading-tone triad may also be regarded as an incomplete dominant seventh chord: "A chord is called 'Incomplete' when its root is omitted. This omission occurs, occasionally, in the chord of the dom.-seventh, and the result is a triad upon the leading tone." : { \override Score.TimeSignature • 'stencil = ##f \override Score.SpacingSpanner.strict-note-spacing = ##t \set Score.proportionalNotationDuration = #(ly:make-moment 1/4) \time 4/4 \relative c'' { 1^\markup { \column { "Leading-" "tone triad" } } ^\markup { \column { "Dominant" "seventh chord" } } } } {{Image frame|content= \new PianoStaff 4 } >> \new Staff > >> |width=300|caption=A leading-tone triad (beat 4) and secondary leading-tone triad (beat 6) in the first phrase of the Bach chorale "Gott der Vater, wohn' uns bei" (slightly simplified)}} Some sources say the chord is not a chord; some argue it is an incomplete dominant seventh chord, especially when the diminished triad is written in its first inversion (resembling a second inversion dominant seventh without a root): For example, vii often substitutes for V, which it closely resembles, and its use may be required in situations by voice leading: "In a strict four-voice texture, if the bass is doubled by the soprano, the VII [vii] is required as a substitute for the V". Voice leading Since the leading-tone triad is a diminished triad, it is usually found in its first inversion: According to Carl Edward Gardner, "The first inversion of the triad is considered, by many, preferable to root position. The second inversion of the triad is unusual. Some theorists forbid its use." In a four-part chorale texture, the third of the leading-tone triad is doubled in order to avoid adding emphasis on the tritone created by the root and the fifth. Unlike a dominant chord where the leading tone can be frustrated and not resolve to the tonic if it is in an inner voice, the leading tone in a leading-tone triad must resolve to the tonic. Commonly, the fifth of the triad resolves down since it is phenomenologically similar to the seventh in a dominant seventh chord. All in all, the tritone resolves inward if it is written as a diminished fifth (m. 1 below) and outward if it is written as an augmented fourth (m. 2). : \new Voice \relative c' { \clef treble \key c \major \time 4/4 2 \bar "||" 2 \bar "||" } == Leading-tone seventh chord ==

{{Image frame|content= \new PianoStaff 4.( 8) 4( -.) ->( -.) ->( -.) r } >> \new Staff ( 2-> 4 2 4 ) r r } >> >> |width=425|caption=Leading-tone seventh chords (with suspensions) functioning as dominant chords in Beethoven's Piano Sonata No. 5, mvmt. I.}} The leading-tone seventh chords are vii7 and vii7, the half-diminished and diminished seventh chords on the seventh scale degree () of the major and harmonic minor. For example, in C major and C minor, the leading-tone seventh chords are B half-diminished (B–D–F–A) and B diminished (B–D–F–A), respectively. Leading-tone seventh chords were not characteristic of Renaissance music but are typical of the Baroque and Classical period. They are used more freely in Romantic music but began to be used less in classical music as conventions of tonality broke down. They are integral to ragtime and contemporary popular and jazz music genres. Composers throughout the common practice period often employed modal mixture when using the leading-tone seventh chord in a major key, allowing for the substitution of the half-diminished seventh chord with the fully diminished seventh chord (by lowering its seventh). This mixture is commonly used when the leading-tone seventh chord is functioning as a secondary leading-tone chord. The example below shows fully diminished seventh chords in the key of D major in the right hand in the third movement of Mozart's Piano Sonata No. 5 in G major. : \new PianoStaff 8 e'16[ dis fis e] \once \override DynamicLineSpanner.staff-padding = #3.5 g16([\p e cis bes)] \once \override DynamicLineSpanner.staff-padding = #3.5 a8\f g'16([ e cis bes)] \once \override DynamicLineSpanner.staff-padding = #3.5 a8\f g'16([ e cis bes)] \once \override DynamicLineSpanner.staff-padding = #3.5 a8\f g'16([ e cis bes)] \once \override DynamicLineSpanner.staff-padding = #3.5 a8\f r r \f } >> \new Staff r8 r r8 r r8 r \clef bass \once \override DynamicLineSpanner.staff-padding = #3.5 d,16([^\p fis a d)] fis8 } >> >> : Function The leading-tone seventh chord has a dominant function and may be used in place of V or V. Just as vii is sometimes considered an incomplete dominant seventh chord, a leading-tone seventh chord is often considered a "dominant ninth chord without root".) : { \override Score.TimeSignature • 'stencil = ##f \override Score.SpacingSpanner.strict-note-spacing = ##t \set Score.proportionalNotationDuration = #(ly:make-moment 1/7) \time 4/4 \relative c'' { 1^\markup { \column { "Leading-tone" "seventh chord" } } ^\markup { \column { "Dominant minor" "ninth chord" } } } } For variety, leading-tone seventh chords are frequently substituted for dominant chords, with which they have three common tones: "The seventh chord founded upon the subtonic [in major]... is occasionally used. It resolves directly to the tonic... This chord may be employed without preparation." Voice leading In contrast to leading-tone triads, leading-tone seventh chords appear in root position. The example below shows leading-tone seventh chords (in root position) functioning as dominants in a reduction of Mozart's Don Giovanni, K. 527, act 1, scene 13. : { > \new PianoStaff r r r r r r r } >> \new Staff r b r r b r r b r r } >> >> >> } François-Joseph Fétis tunes the leading-tone seventh in major 5:6:7:9. == See also ==