SUMMARY
In Srecko Koporc's (1900–1965) estate numerous theoretical writings on music have been preserved. So far, we know of ca twenty notebooks that came into being between 1926, when he wrote the first part of his theory of musical form, and 1960, when he finished his Orchestration. The article gives a short insight into Koporc's music theory which has hardly been researched by Slovene musicology, and which – due to the ange of accessible material – is opening the way to further investigation.