Theo van Doesburg (Dutch, 1883-1931), Composition in Gray (Rag-time), 1919. Oil on canvas, 96.5 × 59.1 cm, The Solomon R. Guggenheim Foundation.
From The Solomon R. Guggenheim website:
This work of 1919 demonstrates van Doesburg’s lingering attachment to what he disdainfully referred to as the “brown” world of Cubism. Reluctant to diffuse the composition, he structures monochromatic, modulated planes around a central axis and allows the lower corners to recede, thereby suggesting a Cubist oval. According to the dogma of the “white” world of Neo-Plasticism, the focus should be moved from the center of the canvas to its periphery; the rectangle should not be construed as a discrete plane but as a shape passively resulting from the intersection of lines and given substance by color. However, Composition in Gray (Rag-time) incorporates aspects of the Neo-Plastic aesthetic that distinguish its style from Analytic Cubism. For example, the edges of its planes have been regularized and contoured and do not penetrate or overlap one another. Despite the illusion of bowing in individual planes, they have been organized with architectural clarity as a rhythmic composition that is essentially flat and frontal.