DOMINANT (subst.). Of the three notes essential to the tone, it is that which is a fifth from the tonick.—The tonick and the dominant fix the tone: in it they are each of them the fundamental sound of a particular chord; whereas the mediant, which constitutes the mode, has no chord peculiar to itself, and only makes a part of the chord of the tonick.
Mr Rameau gives the name of dominant in general to every note which carries a chord of the seventh, and distinguishes that which carries the sensible chord by the name of a tonick dominant; but, on account of the length of the word, this addition to the name has not been adopted by artists: they continue simply to call that note a dominant which is a fifth from the tonick; and they do not call the other notes which carry a chord of the seventh dominants, but fundamentals; which is sufficient to render their meaning plain, and prevents confusion.
A dominant, in that species of church music which is called plain-chant, is that note which is most frequently repeated or beaten, in whatever degree it may be from
the tonick. In this species of music there are dominants and tonicks, but no mediant.