Issues concerning relations between the parts for two instruments and is effect on the tone form in the course of development of the form are discussed in the article. The authoress performs exemplification of the issue on the grounds of case studies of four violin sonatas written by Polish composers in different periods of the 20th century. They are:
— Sonata in G-major for violin and piano by Henryk Melcer (1907),
— Sonata for violin and piano by Roman Maciejewski (1938),
— Sonata No 4 for violin and piano by Grażyna Bacewicz (1949),
— Sonata for violin and piano by Eugeniusz Knapik (1971).
Deliberations on the texture-tone phenomena in these compositions are preceded by a methodo-
logical introduction, entitled “Tone as a Research Problem”. Opinions expressed by, among others, Carl Dalhaus, Igor Stravińsky, Ryszard D. Golianek, Józef M. Chomiński are also discussed.
Analyses of subsequent works lead to conclusions on types of the applied texture, methods of operating instrumental registers and variations of inter-instrumental relations. In each sonata, the conclusions are different. In the Sonata in G-major by Henryk Melcer, there are relations of a successive dialogue, giving a selective tone and simultative cooperation (parallel narration) forming three tone variants: uniform, complementary and contrasting. The second composition,Sonata by Roman Maciejewski, shows aspiration to the texture-tone combination. Sonata No. 4 byGrażyna Bacewicz achieves a high degree of variability with a majority of contrasting simultativecooperation. The last Sonata by Eugeniusz Knapik, assuming the plane model with strong con- trasts in planning tone arrangements, creates a “terrace tone form”.
Each sonata presents its own model (also stylistic) of shaping tone and texture, and the final shape of the tone is affected by its idiolect form, resulting from, above all, the individual style of a given composer.