Mediant

In music,mediant isthird degree ofdiatonic scale. For example, inC major scale (white keys onpiano),mediant isnote E; andmediant chord usesnotes E, G,B. In music theory,mediant chordsymbolized withRoman numeral III if major or iii if minor.

"Mediant" also refers torelationshipmusical keys. For example, relative tokeyC major,keyE major ismediant. Modulation (changeskey) tomediantrelatively rare, compared with, say, modulation intodominant.