Musical material - themes, motifs, and their components - emerges in the music of the 19th century through new combinations throughout compositions. The term 'synthesis' is introduced for the various structures, accompanied by differentiating adjectival specifications. Syntheses can assume different functions throughout the pieces. The author analytically examines the motivic and formal structures as well as their functions and considers the motivic-thematic process that produces and determines these syntheses. This results in a nuanced picture of the material and formal conditions, even beyond familiar schemas.