Supertonic

In music or music theory, the supertonic is the second degree or note of a diatonic scale, one step the tonic. It is sung as re in solfege. 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 ii^o 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, ♯ii^o⁷.