Mediant

In music, the mediant (Latin: to be in the middle) is the third scale degree of a diatonic scale, being the note halfway between the tonic and the dominant. It is sung as mi in solfege. Similarly, the submediant is halfway between the tonic and subdominant. The fifth note is almost always a perfect fifth, while the third note can equally be a minor or major third.

Schenkerian analysts consider this scale degree as expansion of the Tonic since they have two common tones. On the other hand, in German theory derived from Hugo Riemann the mediant in major is considered the dominant parallel, Dp, and in minor the tonic parallel, tP (see: parallel chord).

In Roman numeral analysis, the mediant chord can take several forms. In major scales, the mediant chord is minor and is noted with the Roman numeral iii. In a natural minor scale, the mediant occurs as a major chord, noted with the Roman numeral III. In harmonic minor scales and ascending melodic minor scales, the seventh scale degree is raised by a half-step from a subtonic to a leading tone, creating an augmented mediant chord, noted with the Roman numeral (♭)III⁺.

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