Paul taught at the Bauhaus from 1921-1926 in Weimar and from 1926-1931 in Dessau. He was a form master in book binding and in charge of workshops for stain glass and mural painting. He became more interested in lines and structure, like the use of a grid. He wrote about his ideas on color theory and painting. "Klee used the musical term "polyphonic" (many voiced) in titles to draw attention to the simultaneous sounds created by the various pictorial elements ands stylistic devices in his painting. Whereas the composistion of Polyphonic Setting for White is kept relatively simple and transparent, a narrative element increases the complexity in the watercolor Battle Scene from the Comic-Operatic Fantasy" the Seafarer." "The use of layers of color over a drawing could, according to Klee, be compared to a polyphonic musicaL composition. Thus, at the outset of his Bauhaus period, Klee demonstrated both poles of his art in the creative fusing of the fantastic-imaginative with the constructive-formative-both of which are intrinsic to music as well as derived from it."
Klee was still influenced by Wassily Kandinsky, Lyonel Feininger, Alexej Jawlensky. They formed the Blaue Vier in 1924. And they showed an exhibit in New York, U.S.A. and in Paris. In 1930 Klee had an exhibition at the Museum of Modern Art. He then went to teach at the akademie in 1931 after the Nazis closed the Bauhaus school. Seventeen of Paul Klee's paintings were exhibited by the Nazis as "degenerate art."