According to generally accepted ideas the method of “synthetic chords” by Roslavets is based on free alternation of transpositions of the selected complicated chord. But the detailed analysis of the composer’s manuscripts and sentences shows that his ideas were different. The synthetic chord is defined as the unique structure of six tones that includes the basic chords of classic harmony and represents the mode (or key). The relations of transpositions of synthetic chords are reflected in the form of original schemes of “key-relationship”. The principle of construction of such schemes is closely linked to the composer’s interests in the field of the music theory.