Mediant

In music, the mediant (Latin: "being in the middle") is the third scale degree of a diatonic scale, being the note halfway between the tonic and the dominant. In the movable do solfège system, the mediant note is sung as mi. While the fifth scale degree is almost always a perfect fifth, the mediant can be a major or minor third.

Schenkerian analysts consider the mediant (third scale degree) as an expansion or extension of the tonic since they are both common tones of the tonic chord. Thus, the third degree of a tonic triad is also the mediant iii note; furthermore, the 5th degree of the submediant chord vi is also the mediant iii note. 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.

In Roman numeral analysis, the mediant chord can take several forms. In major scales, the mediant chord is a minor triad and is symbolized with the Roman numeral iii. In natural minor scales, the mediant is a major triad and is symbolized 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 the subtonic b7 to the leading tone natural 7, creating an augmented triad that is symbolized with the Roman numeral bIII+ (flat III augmented).