In his native Japan, Takeo Yamaguchi was a pioneer of modern abstract painting. This focus led him to spend time in France, where he was much influenced by the work of Cubist practitioners in Paris, until he returned to Japan in 1931. In the 1950s, Yamaguchi began executing works consisting of simple, geometric forms—largely yellow, ochre, or russet in color—painted on a black background. His thick pigments added texture to the monochromatic compositions, and as seen in Work—Yellow (Unstable Square [Fuantei shikaku], 1958), Yamaguchi’s abstract shapes increasingly dominated the canvas. It is noteworthy that the painting was prominently displayed on the ground floor of the Guggenheim’s rotunda during the 1959 inaugural exhibition, attesting to then-director James Johnson Sweeney’s keen interest in Yamaguchi’s work.