Supertonic

In music, the supertonic is the second degree () of a diatonic scale, one whole step above the tonic.^[1] In the movable do solfège system, the supertonic note is sung as re.

${ \override Score.TimeSignature #'stencil = ##f \relative c' { \clef treble \time 7/4 c4 \once \override NoteHead.color = #red d e \once \override NoteHead.color = #red f g \once \override NoteHead.color = #red a b \time 2/4 c2 \bar "||" \time 4/4 <d, f a>1 \bar "||" } }$

${ \override Score.TimeSignature #'stencil = ##f \relative c' { \clef treble \time 7/4 c4 \once \override NoteHead.color = #red d es \once \override NoteHead.color = #red f g \once \override NoteHead.color = #red aes bes \time 2/4 c2 \bar "||" \time 4/4 <d, f aes>1 \bar "||" } }$

The scale and supertonic triad in C major (top) and C minor (bottom).

The triad built on the supertonic note is called the supertonic chord. In Roman numeral analysis, the supertonic chord is typically symbolized by the Roman numeral "ii" in a major key, indicating that the chord is a minor chord (in C: D–F–A). In a minor key, it is indicated by "ii^o" if it is built on the a natural minor scale, indicating that the chord is a diminished chord (in C: D–F–A♭). Because it is a diminished chord, it usually appears in first inversion (ii^o6) so that no note dissonates with the bass note.

These chords may also appear as seventh chords: in major, as ii⁷ (in C: D–F–A–C), while in minor as ii^ø⁷ (in C: D–F–A♭–C) or rarely ii⁷. They are the second-most-common form of nondominant seventh chords.^[2]

${ \override Score.TimeSignature #'stencil = ##f \relative c' { \clef treble \time 4/4 \key c \major <d f a c>1_\markup { \concat { "ii" \raise #1 \small "7" } } \bar "||" \clef treble \time 4/4 \key c \minor <d f aes c>1_\markup { \concat { "ii" \raise #1 \small "ø7" } } <d f a c>^\markup { "rare" }_\markup { \concat { "ii" \raise #1 \small "7" } } \bar "||" } }$

ii⁷ (first and third chords)

ii^ø⁷ (second chord)

The supertonic chord normally functions as a predominant chord, a chord that naturally resolves to chord with dominant function. The supertonic chord lies a fifth above the V chord. Descending fifths are a strong basis for harmonic motion (see circle of fifths). The supertonic is one of the strongest predominants and approaches the V chord from above by descending fifth.

In major or minor, the major chord built on the lowered supertonic (♭) is called a Neapolitan chord (in C: D♭–F–A♭), notated as N⁶ or ♭II⁶, usually used in first inversion. The supertonic may be raised as part of the common-tone diminished seventh chord, ♯ii^o⁷ (in C: D♯–F♯–A–C). One variant of the supertonic seventh chord is the supertonic diminished seventh^[3] with the raised supertonic, which equals the lowered third through enharmonic equivalence (in C: D♯=E♭).

The term supertonic may also refer to a relationship of musical keys. For example, relative to the key of C major, the key of D major (or D minor) is the supertonic.

In Riemannian theory, the supertonic is considered the subdominant parallel: Sp/T in major though sP/T in minor (A♭M).

References

^ Benward & Saker (2003). Music: In Theory and Practice, Vol. I, p. 32. Seventh edition. ISBN 978-0-07-294262-0. "One step above the tonic."
^ Kostka, Stefan; Payne, Dorothy (2004). Tonal Harmony (5th ed.). Boston: McGraw-Hill. p. 216. ISBN 0072852607. OCLC 51613969.
^ Kitson, C. H. (2006). Elementary Harmony, p. 43. ISBN 1-4067-9372-8.

[1] Benward & Saker (2003). Music: In Theory and Practice, Vol. I, p. 32. Seventh edition. ISBN 978-0-07-294262-0. "One step above the tonic."

[K&P_246-2] Kostka, Stefan; Payne, Dorothy (2004). Tonal Harmony (5th ed.). Boston: McGraw-Hill. p. 216. ISBN 0072852607. OCLC 51613969.

[3] Kitson, C. H. (2006). Elementary Harmony, p. 43. ISBN 1-4067-9372-8.

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