The purpose of this paper. The purpose of the study involves a thorough study on the genre system of choral heritage I. Shamo, as understanding the genre essence of choral work is an essential component of performing interpretation.
 The methodology. Methodological principles are the principle of historicism, historical-contextual method, genre-style analysis and acmeological method in musicology, used to understand the top achievements of I. Shamo in the context of the evolution of artistic thinking of the artist.
 The results. The genre system of I. Shamo’s choral heritage consists of the genres of choral song, suite, choral cycle, cantata, cantata-poem, cantata-oratorio, choral opera a cappella, oratorio (concert-performance). The directions of the composer’s creative search in the genre of choral song are connected with the usage of different choral compositions, appeal to the genres of lyrical song, stylization of ritual songs, romanticization of patriotic song. It is determined that the semantics of the first cycle of choirs a cappella by I. Shamo in the poem by I. Franko reveals the theme of the cycle of the seasons, drawing a parallel with the stages of human life. For the choral cycle “Flying Cranes”, the name of which is a symbol of unattainable happiness and, at the same time hope, the composer improves the techniques of sound recording, creates expansive melodic lines based on a synthesis of folk and romantic intonations. The third cycle of I. Shamo “10 choirs on the poems of Ukrainian poets” demonstrates the latest achievements of the artist in choral writing, timbre drama, the implementation of the principles of working with folk poetic sources, characteristic of the “second wave of folklore”. It is substantiated that the unity of the “Carpathian Suite” of the composer is promoted by: tonal plan, contrasting tempo drama and artistic sound images, intonational unity based on the theme of Ukrainian folk models. Based on the author’s genre definitions of the “Yatran Games”, it is determined that in I. Shamo’s choral opera a cappella there is a synthesis of genres: suite, choral scenes originated from folk life and ceremonial action under the auspices of the opera genre. It was found that among the genres of orchestral and choral compositions of the artist — cantata, cantata-poem, cantata-oratorio, which is dominated by civic themes. Innovative is the work of I. Shamo “Skomoroshyny”, which synthesizes the genres of oratorio and concert, with theatricalization of these genres. The choral opuses showed such features of the artist’s style as the synthesis of genres, the tendency to cyclicality, reliance on national roots, the creation of author’s melodies, where deep folklore manifestations, sprechstimme, sonorism, aleatorics.
 The scientific creativity lies in the analysis of the components of the genre system of I. Shamo’s choral heritage, in the awareness of the genre phenomenon of each choral work and in the identification of the evolution of the artist’s style.
 The practical significance of the obtained results is due to the need to determine the genre of choral work to create a performing interpretation.