The purpose of the study is to reveal the figurative, semantic and symbolic specificity of the interpretation of the timbre of "Martenaut waves" in the music of the French avant-garde cinematography of the first half of the 20th century, including in the work of A. Honegger. Research methodology. Cultural-historical, interdisciplinary historical-cultural, as well as analytical-musicological methods were essential for this work. The scientific novelty of the work lies in the fact that it introduces for the first time into the circulation of art historians the materials related to the film music of A. Honegger and its timbral specificity, marked by an appeal to the semantic and expressive features of the "Martenaut waves". Conclusions. At the turn of the 19th and 20th centuries, as a result of rapid scientific and technical progress, cinematography came to the forefront of world art. The unity of cinematography as a synthetic art and music is strengthened by the emergence of sound cinema in 1926-1927, in which music is recorded on the same film as the image. The use of electric musical instruments, including "Martenaut waves", becomes organic in this process. Thanks to their unusual timbre, they acquired the meaningful status of the embodiment of "the materialisation of the intangible." The world of hallucinations and dreams, mystical spiritual revelations and unusual natural phenomena – such was the range of images that were conveyed with the help of this instrument in French film music of the 1930s and 1940s. A. Honegger worked most fruitfully in this field during the mentioned period, whose creative output includes more than forty soundtracks, including those using "Martenaut waves". One of the first films in which the expressive timbre of this instrument is used was the science fiction film "The End of the World" (1931) directed by A. Gans, as well as the animated film "Idea" (1934) directed by B. Bartosh and artist F. Mazerel. In the musical accompaniment of these films, the timbre of the "Martenaut waves" occupies almost the most important place, revealing the connection of the instrument with the sphere of the Sacred and the Cosmic and the spiritual and stylistic searches of European modern culture.