And we have the decisive fact that of the six scales of the cithara given by Ptolemy ([see p. 85]) not one is diatonic in the modern sense of the word. It may be alleged on the other side that the ideal scale in the Timaeus of Plato is purely diatonic, and exhibits the strictest Pythagorean division. But that scale is primarily a framework of mathematical ratios, and could not take notice of intervals which had not yet been identified with ratios. It is not certain when the discovery of Pythagoras was extended to the non-diatonic scales. Even in the Sectio Canonis of Euclid there is no trace of knowledge that any intervals except those of the Pythagorean diatonic scale had a numerical or (as we should say) physical basis [62]. In Plato's time, as we can see from a well-known passage of the Republic (quoted on [p. 53]), the Enharmonic and Chromatic scales were the object of much zealous study and experiment on the part of musicians of different schools,—some seeking to measure and compare the intervals directly by the ear, others to find numbers in the consonances which they heard, and both, from the Platonic point of view, 'setting ears above intelligence,' and therefore labouring in vain [63].
The multiplicity of intervals, then, which surprises us in the doctrine of the genera and 'colours' was not an accident or excrescence. And although some of the finer varieties, such as the Enharmonic, belong only to the early or classical period, there is enough to show that it continued to be characteristic of the Greek musical system, at least until the revival of Hellenism in the age of the Antonines. The grounds of this peculiarity may be sought partly in the Greek temperament. We can hardly deny the Greeks the credit of a fineness of sensibility upon which civilisation, to say the least, has made no advance. We may note further how entirely it is in accordance with the analogies of Greek art to find a series of artistic types created by subtle variations within certain well-defined limits. For the present purpose, however, it will be enough to consider how the phenomenon is connected with other known characteristics of Greek music,—its limited compass and probably imperfect tonality, the thin and passionless quality of its chief instrument, on the other hand the keen sense of differences of pitch, the finely constructed rhythm, and finally the natural adaptation, on which we have already dwelt, between the musical form and the language.
The last is perhaps the feature of greatest significance, especially in a comparison of the ancient and modern types of the art. The beauty and even the persuasive effect of a voice depend, as we are more or less aware, in the first place upon the pitch or key in which it is set, and in the second place upon subtle variations of pitch, which give emphasis, or light and shade. Answering to the first of these elements ancient music, if the main contention of this essay is right, has its system of Modes or keys. Answering to the second it has a series of scales in which the delicacy and variety of the intervals still fill us with wonder. In both these points modern music shows diminished resources. We have in the Keys the same or even a greater command of degrees of pitch: but we seem to have lost the close relation which once obtained between a note as the result of physical facts and the same note as an index of temper or emotion. A change of key affects us, generally speaking, like a change of colour or of movement—not as the heightening or soothing of a state of feeling. In respect of the second element of vocal expression, the rise and fall of the pitch, Greek music possessed in the multiplicity of its scales a range of expression to which there is no modern parallel. The nearest analogue may be found in the use of modulation from a Major to a Minor key, or the reverse. But the changes of genus and 'colour' at the disposal of an ancient musician must have been acoustically more striking, and must have come nearer to reproducing, in an idealised form, the tones and inflexions of the speaking voice. The tendency of music that is based upon harmony is to treat the voice as one of a number of instruments, and accordingly to curtail the use of it as the great source of dramatic and emotional effect. The consequence is twofold. On the one hand we lose sight of the direct influence exerted by sound of certain degrees of pitch on the human sensibility, and thus ultimately on character. On the other hand the music becomes an independent creation. It may still be a vehicle of the deepest feeling: but it no longer seeks the aid of language, or reaches its aim through the channels by which language influences the mind of man.
APPENDIX
Table I.