Of all arts, music is accredited to be the highest and purest. The supreme art of the beautiful, it rests on a mathematical basis. Its notes and intervals and chords progress in compliance with defined, or at least definable laws corresponding to the great laws which, moving with mathematical precision, brought order from chaos and so created the world. Concerning the art of sound, this problem confronts us; what are the laws if any which govern the ugly? Or, to put it differently, to what extent does the ugliness of evil correspond to chaotic conditions? If what the composer would depict is not governed by mathematical law, then is he warranted in the use of unresolved and unresolvable dissonances. Judged by this rule, Debussy has perhaps so transgressed that a wiser generation will pronounce his efforts to be a passing phase of æstheticism. But the difficulty of determining just what is, or is not governed by mathematical law, must lead to a deal of error ere we attain the true art of sound. To illustrate the vast unlikeness of method in the descriptive instrumental works of the classical and those of the ultra-modern school, two examples will suffice. The representation of Chaos in Haydn's «Creation,» gave to the composer full opportunity for every liberty of harmony and form tolerated in his time. Now, while a rather frequent use of the diminished seventh chord lends to this composition somewhat of needed vagueness, still there are no modulations to distant keys, no abrupt transitions, no unresolved or unresolvable discords, no consecutive perfect fifths, and, in fact, there is nothing in the chord progression which the critic of to-day would deem daring or even unusual for, always and wholly, the harmonic scheme conforms to conventional rules. Here and there is somewhat of concession to established musical form, for, in this picture of Chaos, the employment of anything radical either in form or harmony, would have provoked censure the very harshest and even have proved the author guilty of the unpardonable sin of producing what could never be called music. With this attempted realism of Haydn, compare now that portion of «Don Quixote» wherein Strauss delineates the gradual and complete disordering of the mind of Cervantes' hero. Wholly sure of his novel method, one, by the way, peculiarly adapted to the subject, Strauss avails himself of every conceivable liberty of tone and form. Euphony and cacophony mix in an astounding realism, while the rational sequence of sanctioned form gives way to the illogical and wholly fantastic, in fact the chaos of dethroned reason. III