The purpose of this study is to show—by means of a rigorous analysis of the harmonic principles which govern the multiple sections of the work—that beyond the apparently heterogeneous surface the musical discourse of “Tantris the Clown” from the Masks, op. 34 by Karol Szymanowski is subtly and coherently organised by the interpenetration of two layers: the immediate perception of sound structure and the underlayer which proceeds from the order of the harmonic fundamentals. This article also proposes suggestions for interpretation, determined by the analytical experience.