ESSENTIAL DISCORDS AND RIGID TONALITY The strict theory of suspensions and passing-notes was diversi fied by many idioms which grew up charmingly and illogically. Logic itself admitted harshnesses which the pure taste of Victoria and Palestrina rejected without waiting for the judgment of theorists. For instance, our glorious Tudor masters shared with many other composers outside the Hispano-Roman orbit a keen intellectual pleasure in violent collisions between a major and a minor 3rd over the same bass; some 3rd being essential to the harmony and each of the conflicting voices having unanswerable reasons for its own version. But these "false relations," as we now call them, are both archaic and provincial, for all their logic. The overlapping of harmonic ideas produced many results both more pleasant and more fruitful.
Here is an extreme case in which the ordinary rules of musica ficta give results which strain the i 9th century theorist and compel him to discover "double roots" and other cabalistic secrets.
The bass singer, knowing his rules of musica ficta, would be insulted at such a "donkey's mark" as a flat to the B for the purpose of correcting the inadmissible tritone, comprised between F and B. The treble singer would automatically sharpen his G, under the impression that he was making a close on A; and so the augmented 6th, one of the most complex discords known to Bach and Mozart, did frequently occur in i 6th century per formances and was not always regarded as a blunder. In Ex. 12 the treble singer would happen to be mistaken in sharpening the G, for it is not really part of a close on to A. The close is on to D, and the middle singer would recognize its leading-note without the aid of "donkey's marks." For our Boeotian age we require a flat to the B in the bass and sharps for the penultimate Cs in the middle part. If the 16th century composer intended to pro duce an augmented 6th, he would provide the soprano with a sharp to the G in order to reassure the singer.
But the beginning of the i 7th century saw a musical revolution far beyond the scope of any accumulation of licences on the poly phonic basis. The feeble efforts of the first Monodists, Jacopo Peri, Emilio Cavalieri and other pioneers of opera and solo vocal declamation with lute or keyboard accompaniment, had already drawn attention to the value of any and every chord as a thing in itself, apart from its position in a polyphonic flux, when the masterful spirit of Monteverdi gave to the new movement all the power of his intellect and rhetorical instinct. Only a poly phonist can appreciate the real aesthetic values of monody, and Monteverdi was a vigorous, though decadent polyphonist, both before and of ter he took up monody. But not even his mastery could organize the chaos that overwhelmed the art of music when the limitations of the golden age had been broken down. For one thing, pure polyphony dealt only with unaccompanied voices. When instruments were treated as important elements in serious music the polyphonic hypothesis became inadequate and several new sets of laws had to be found by experiment. A century was no long time for such a task.
Monteverdi's chief innovation is popularly said to be the "in vention" of the dominant 7th and of other so-called "essential" discords. An essential discord is merely a discord which through custom has ceased to require preparation ; and to attribute its invention to any particular author is like naming the first writer who used a metaphor instead of a full-blown simile. Most, if not all, of the discords that have become essential are based on that part of the key which we call the dominant; for the reason that all harmonic phenomena gravitate towards the full close as in evitably as all verbal statements gravitate round the subject predicate-copula group. The dominant of a key is the bass of the penultimate chord of an authentic cadence. Opposed to the dominant there is another centre, the subdominant, which sup ports the penultimate chord of a plagal cadence. A key has, then, three cardinal points : the key-note, or tonic ; the dominant, the chief means of orientation in modulations; and the subdominant, whose function we should understand much more readily if we called it the anti-dominant.
The chief and not wholly unconscious aim of the successors of Monteverdi (that is to say, of the composers of the mid-i 7th century) was to establish the tonic-dominant-subdominant orien tation of major and minor keys in a system which could digest essential discords. A modal composition visited other modes than its own whenever it made a cadence other than on its own final; but it did not establish itself in the visited modes; and still less did it go into regions that produced its own mode at a different pitch.
Throughout the I 7th century the various streams of music were trickling gently towards a mighty lake, from which all later music takes its origin. Alessandro Scarlatti (q.v.) is now less known to us than his wayward son, Domenico, whose harpsichord music is in a genre by itself. But Alessandro, more than any other composer in history, deserves to be considered the founder of a great classical tradition. He is called the founder of the Neapolitan school. And classical tonality is primarily Neapolitan. It recog nizes only two modes—the major and the minor. The loss of modal subtleties is more than compensated by the powerful dramatic and architectonic values of clearly-established keys with a capacity for modulation to similar keys in relations of clear harmonic significance.
The following eight bars from the end of the first recitative in Handel's Messiah, epitomize several normal features of the system: Before discussing this example, we must further explain the system of major and minor keys. Here are the first six degrees of the scale of C major (which, being without sharps and flats, is taken as the standard key) with a triad, or common chord, on each. The notes of these triads are all within the key. The functional names of each degree are given below, and the number above in Roman figures. Capital figures indicate major chords and small figures minor.
The 7th degree, or leading-note, bears no common chord within the key, for its triad has an imperfect 5th. The submediant is so called because the subdominant is not conceived as the note below the dominant, but as an anti-dominant, a fifth below the tonic, so that there is a submediant as a 3rd between it and the tonic, just as there is a mediant as a 3rd between the tonic and dominant.
Another most important gain of the new tonality as against the modal system is that the minor mode can now so firmly support its tonic by its other chords that a minor tonic chord becomes con vincing as a final. The contrast between major and minor keys acquires a high emotional value. We must clearly understand that the minor mode, like the minor triad, is identified with the major mode on the same tonic. The so-called "relative major" is one of five equally direct relations to a minor tonic and the "relative minor" is one of five to a major tonic. The minor mode of C is not (as the Tonic Sol-fa system will have it) A minor, but C minor.
In the minor mode a strict confinement to cardinal harmonies produces a melodically awkward augmented 2nd between the flat 6th and the necessarily sharp leading-note. Accordingly the external form of the scale varies and the variations have harmonic results. Ex. 15 shows the so-called harmonic and melodic minor scales.
The melodic form avoids the augmented 2nd by sharpening the 6th in ascent and flattening both 6th and 7th in descent.