The Komsomol disapprove of Mels new found love of Jazz and 'western' influences, they preform a powerful song about conformity, "fused with one chain, tied to one aim".
The accusing Komissar actually loves Mels but hell have no fury like a woman scorned.
This is from Stilyagi, a Russian movie about rebellious kids in 1950s Russia who followed Jazz and Westernized ideals of living lavishly, their aim was emulation but in eventuality they created a movement all their own. The movie outlines how these Stilyagi were thought of as outcasts and depraved lunatics by most of society back then. A funny scene shows the Kommissar telling Mels at one point that "there is a single step between a saxophone and a knife".