It is perhaps only in the compositions subsequent to Opus 50 that Scriabine emerges in the fullness of his stature. For it is only in them that he finally abandoned the major-minor system to which he had hitherto adhered, and substituted for it the other that permitted his exquisite delicious sense of pianistic color, his infinitely delicate gift of melody, his gorgeous, far-spreading harmonic feeling, free play. And it is only in these later pieces that he achieved the perfection of form, particularly of the sonata form, of which the Ninth Sonata is the magistral example, and which makes his craft comparable to Bach's in its mastery of a medium, and enables one to mention the "Chromatic Fantasy and Fugue" and the Ninth Sonata justly in a single breath. And yet, the compositions of the middle period, the one that follows immediately the early, immature, Chopinesque period, are scarcely less rich and refined, scarcely less important. No doubt the influence of Scriabine's masters, though considerably on the wane, is still evident. The "Poeme satanique" refines on Liszt. The Third Sonata, despite its lambent andante, is patently the work of one who has studied his Liszt and loves his Chopin. And yet, these works are characteristically male and raging and proud. And in all the works of this period there appears something new and magnificent that has scarcely before informed piano music. There is a truly Russian depth and vehemence and largeness in this now languid, now mystical, now leonine music, that lifts it entirely out of the company of the works of the Petrograd salon school into that of those composers who made orchestra and opera speak in the national tongue. The rhythms are joyously, barbarically, at times almost frenetically, free. They are finely various and depart almost entirely from the one-two, one-two, the one-two-three, one-two-three that makes monotonous so much of Chopin. At moments, the tones of the piano march with some of the now festive, now majestic, now solemn, movement of the orchestral processionals of a Moussorgsky and a Borodin. And one has the sense of having encountered only in sumptuous Eastern stuffs, in silken carpets and golden mosaics, or in the orchestral faery of some of the Russian composers, in the orchestral chemistry of, say, a Rimsky-Korsakoff, such brimming, delicious colors. Nevertheless, the voluptuousness and vehemence are held in fastidious restraint. Scriabine is always the fine gentleman, intolerant, for all the splendor of his style, of any excess, of any exaggeration, of any breach of taste. And throughout the work, there is evidence of the steady, restless bourgeoning of the exquisite, disquieting, almost Chinese delicacy which in the work of the last period attains its marvelous efflorescence.