however the most notable section was the brilliant "Infernal Dance of the Ogre Kashchey"
What Stravinsky did was take the lengthy horn theme and essentially rhythmically dissect it. so he cuts up different part of the themes and varies how long the theme goes on for. so sometimes it goes on for 3-4 notes than when repeat it could go for 7-9 notes etc, by changing the duration of the theme it ended up creating an interesting rhythmic variation as every time the theme is played the time signature is different. essentially this is a rhythmic development section which was a very interesting alternative to the German development section
in a traditional german development section the melodic fragments are harmonically manipulated, the same melodic fragments are played in different keys. in this piece the melodic fragments are rhythmically manipulated so that the theme are played in different time signatures by compressing or extending the theme. As the melody is consistent the music still sounds coherent and logical to listen to despite it shifting rhythm.
Which made me think how Russia could have adopted Sonata Form while giving a unique spin to it. Tchaikovsky used varied repetition during the so-called "development section" of his symphonies which really makes his development section kinda boring compared to the german model. his deviation was considered an innovative russian spin to the germanic sonata form but i think his variation made things worst. However if he incorporated a Stravinsky-esque rhythmic and timbral development within a sonata form structure you'll still have music that sounds developmental and the climax of the piece while at the same time be uniquely Russian.
if Infernal Dance of the Ogre Kashchey was a development section within a sonata form movement i would believe it to he a brilliant innovation where a composer stay within the spirit of the form while innovating the letter of the law.
unfortunately Firebird wasn't in sonata form and the 3 section that Greenberg sampled are the only listenable and good part of the entire ballet. the rest of the suite is really an incongruent haphazardly mixture of themes that don't gel together. overly dissonant harmonies, music that stops and start with no rhyme and reason, music that exist purely for atmospheric and plot reasons that can only be enjoyed within the context of a ballet rather than pure music reasons.
Sigh if only Stravinsky used his innovation within the format of sonata form structure maybe I could have respected him as a composer instead of writing essentially incidental music to depict extramusical stories.