But if they reveal Rimsky's keenness, they reveal his limitations as well. They bring into sharpest relief the difference between poetic and superficial expressiveness. For Strawinsky has in many instances successfully handled materials which Rimsky not quite satisfactorily employed. The former's early works, in particular "L'Oiseau de feu," and the first act of the opera "Le Rossignol," related to Rimsky's in style as they are, have yet a faery and wonder and flittergold that the master never succeeded in attaining. The music of "L'Oiseau de feu" is really a fantastic dream-bird. "Petrouchka" has a brilliance and vivacity and madness that makes Rimsky's scenes from popular life, his utilizations of vulgar tunes and dances scarcely comparable to it. Nowhere in any of Rimsky's reconstructions of ethnological dances and rites, neither in "Mlada" nor in "Sniegourochka," is there anything at all comparable to the naked power manifest in "Le Sacre du printemps." But it is particularly in his science of orchestration, the sense of the instruments that makes him appear to defer to them rather than to impose his will on them, that Strawinsky has achieved the thing that his teacher failed of achieving. For Rimsky, despite all his remarkable sense of the chemistry of timbres, despite his fine intention to develop further the science which Berlioz brought so far, was prevented from minting a really new significant orchestral speech through the poverty of his invention. His orchestration is full of tricks and mannerisms that pall. One hears the whistling parabolas of the flutes and clarinets of "Scheherazade" in "Mlada," in "Sadko," in a half-dozen works. The orchestra that paints the night-sky of "Mlada" rolls dangerously like that which paints the sea of "Scheherazade" and "Tsar Saltan." The famous "Chanson indou" seems to float vaguely through half his Oriental evocations. But the originality and fecundity and inventiveness that he lacked, Strawinsky to great degree possesses. And so it was given to the pupil to enter the chamber outside of which the master stood all his life, and could not enter, and saw only by peering furtively through the chinks of the door. Rachmaninoff