The article examines the music composed by N. N. Karetnikov for the film “Pervorossiyane” (directed by A. G. Ivanov, E. L. Shiffers; 1967)—the most musically auto­no­mous work of the composer in cinema. The film, based on O. F. Bergholz’s poem “Pervorossiysk,” was banned from release on aesthetic grounds and remained little known during the composer’s life­time. The analysis draws on piano sketches from the composer’s personal archive. The article explores the thematic system of the film’s music: the main theme and its diatonic derivative, serially organized the­matic complexes (the fire theme and the Cossack theme), and their development throughout the film. Connections are traced between the music of “Pervo­rossiyane” and Karetnikov’s other film scores and autonomous compositions. It is shown that the musical layer of the film exists rela­tively independently of the visual one—both in the com­poser’s conception and as a result of the director’s editing.