After the Russian Revolution, Russian music changed dramatically. The early 1920s were the era of avant-garde experiments, inspired by the "revolutionary spirit" of the era. New trends in music (like music based on synthetic chords) were proposed by enthusiastic clubs such as Association for Contemporary Music.
In the 1930s, under the regime of Joseph Stalin, music was forced to be contained within certain boundaries of content and innovation. Classicism was favoured, and experimentation discouraged. (A notable example: Shostakovich's veristic opera Lady Macbeth of the Mtsensk District was denounced in Pravda newspaper as "formalism" and soon removed from theatres for years).
The music patriarchs of the era were Prokofiev, Shostakovich and Aram Khachaturian. With time, a wave of younger Soviet composers, such as Georgy Sviridov, Alfred Schnittke, and Sofia Gubaidulina took the forefront due to the rigorous Soviet education system. The Union of Soviet Composers was established in 1932 and became the major regulatory body for Soviet music.
Film soundtracks produced a significant part of popular Soviet/Russian songs of the time, as well as of orchestral and experimental music. The 1930s saw Prokofiev's scores for Sergei Eisenstein's epic movies, and also soundtracks by Isaak Dunayevsky that ranged from classical pieces to popular jazz.
I don't want happiness by halves, nor is half of sorrow what I want. Yet there's a pillow I would share, where gently pressed against a cheek like a helpless star, a falling star, a ring glimmers on the finger of a hand.