Known for his unique pictorial language and innovative teachings at the Bauhaus, Paul Klee had far-reaching influence on 20th-century modernism. In an early attempt to master color, he associated himself with the group Der Blaue Reiter (The Blue Rider), working closely with friend and future Bauhaus colleague Wassily Kandinsky. While engaged with artistic theory, Klee also admired children’s art, wanting his own style to be similarly unaffected. And his dream-like pictures made him popular with the Surrealists, though he never officially became one. Klee’s work can be humorous, his fantastic drawn subjects conveying a playful sense of absurdity, as with his famous Twittering Machine (1922). Later in his career, he began to build up thicker painted surfaces and simplify his compositions, replacing precise line-work with fewer, bolder forms. Klee’s art and lessons on color theory would greatly impact later generations of artists, including, significantly, the Abstract Expressionists and Color Field painters.