Supertonic
In music or music theory, the
supertonic is the second degree or note of a diatonic scale, one step above the tonic. In music theory, the
supertonic chord may be symbolized by the Roman numeral
ii in a major scale, indicating that the chord is a minor chord (for example, D-F-A in C major), or
iio in a natural minor scale, indicating that the chord is a diminished chord (for example, D-F-A♭ in C natural minor), if in second inversion a six-four chord (A♭-D-F), and if the third is raised an augmented sixth chord (A♭-F♯). If in major or minor, through the lowering of the second scale degree (also the sixth in major), the chord is major (D♭-F-A♭) then it is a Neapolitan 6th chord, N6 or ♭II6. The supertonic may be raised as part of the common-tone diminished seventh chord, ♯iio7. The similarity between the subdominant and supertonic chords is easily seen and heard through the
supertonic seventh chord,
ii7, Play (help·info). The
French sixth chord; distinguishing tone highlighted in blue.