Martinmüller's complex system of combining rectangular forms follows a principle comparable to music, whereby the basic square element in conjunction with its color characterization determines the coherence of the motif units. Martinmüller chooses the rectangle as a measurable building block of his creations that can be joined without residue. These elements can be joined in thoughtful construction to form complex orders. From logical arrangements in the horizontal, in the vertical and finally also in the diagonal, the rhythmic structure emerges - unique, unrepeatable. The combinations are developed in lengthy studies and experiments. The realm of sounds, leading tones, intermediate tones that emerge in the end, although comprehensible at all times, ultimately eludes any analytical precision.