Arnold Schoenberg · section 7 of 30

The Diatonic Triads

We begin by building a triad on each tone of the scale after the pattern of the fundamental triad. In doing so—to state here at once a principle that will find many applications later—we transfer to other cases, imitate, what we have observed in a model instance. These triads, however, are not to be fundamental triads like the model, but, for the sake of tonality, free reproductions of the idea: fundamental, third, and fifth, or of the interval numbers 1–3–5. For their thirds and fifths we do not use the intervals inherent in the tone, if one may put it that way—on the second tone of the C-major scale, d, therefore not f♯ and a—but, to secure the effect of tonality even for our first exercises, the diatonic ones, thus f and a. In other words: in the seven chords that we build above the seven tones of the major scale, we use no tones other than these same seven—the diatonic tones.

Thus the triads formed from diatonic tones in C major are as follows:

The individual tones of the scale, insofar as they are roots—that is, the lowest tones of a triad—are called degrees. Thus C in the triad c–e–g is the first degree, D in the triad d–f–a the second degree, E in e–g–b the third degree, and so forth. The triads differ in their construction. We find some in which, reckoning upward, a major third and a minor third adjoining it build up a perfect fifth; others in which the perfect fifth arises in the reverse order, first the minor third, then the major; and one whose diminished fifth is formed from two equal intervals, two minor thirds. Triads of the first kind, major triads, occur on degrees I, IV, and V; the second kind, minor triads, on degrees II, III, and VI; the third kind, the diminished triad, only on degree VII. An important distinction should be pointed out at once. The triad on degree I is indeed a major triad, for it is the triad from which the major key in question takes its name. The two other triads built like it, those on degrees IV and V, are also ordinarily called major triads, and in this sense one speaks of the F-major or G-major triad. But this is actually wrong and confusing. In C major there is only one triad entitled to the name major triad: that on degree I. The other two, degrees IV and V, should never be called F major or G major, because this could create the mistaken impression that a key, a tonality—the key of F major or G major—is meant. It is likewise wrong to speak of degrees II, III, and VI as the D-minor, E-minor, or A-minor triad. It is most practical to use the terms degree I, II, III, and so on, or to say: triad on G or A with a major or minor third. One soon remembers in any case which of these degrees have a major or minor third, which are major-like or minor-like. The names tonic for I, dominant for V, lower dominant or subdominant for IV, upper mediant for III, lower mediant for VI, and diminished triad for degree VII are also used. Under special circumstances degree II also bears a name; this will be mentioned when the occasion arises.

The term dominant for degree V is not entirely correct, strictly speaking. Dominant means the ruling one, and would therefore imply that degree V rules one or more others. Naturally this can only be a metaphor, but even as such it seems incorrect to me, for the fifth tone, the fifth, naturally appears later in the overtone series than the fundamental, and is therefore of less significance for the sound than the fundamental, which occurs earlier and hence more often. The relationship is therefore characterized more by the dependence of the fifth upon the fundamental than by the reverse, the fundamental being ruled by the fifth. If anything dominates, it can only be the fundamental; and every fundamental can in turn be ruled by a tone a fifth below it, in whose overtone series it appears as the fifth, in second place. For the metaphor to be correct, then, the fundamental would have to bear the designation dominant, since something of subordinate importance should not be described as ruling something of superior importance. I retain the term dominant so as not to cause confusion with new terminology, and because, as will be shown later, this chord, though not ruler of the key, does rule a part of it, its upper region, the upper-dominant region. But let it be mentioned at once that much of what I shall say about the values of the degrees with regard to their ability to form successions, chord progressions, rests on this recognition: that the tonic is the ruler and the dominant the ruled.

The name dominant is usually justified by asserting that degree I appears through the effect of degree V. I would then be a consequence of V. But something cannot be the cause of a phenomenon and at the same time also the effect of that same phenomenon. And I is indeed the cause of V, since V is its overtone. Certainly degree V is followed by degree I. But here the two meanings of the word “follow” are being confused. To follow means to obey, but also to come after. And when the tonic follows the dominant, it is only as when a king sends his vassal, master of ceremonies, or quartermaster ahead to make suitable preparations for the arrival of the king, who then admittedly follows him. But the vassal exists because of the king, and not the other way around.