He was one of the most original and prolific artists of the 20th century, painting over 760 panel paintings and 9,000 works. A talented violinist, he played for Berne Symphony Orchestra until 1906, when he settled in Munich, and joined the Blaue Reiter group 1912. He taught at the Bauhaus school of design 1921-31, when he took up a Professorship at the Dusseldorf Art Academy, from which post he was dismissed by the Nazis 1933, when he returned to Switzerland. Endlessly inventive and playful, his many works are an exploration of the potential of line, plane, and colour. Suggesting a childlike innocence, they are based on the belief in a reality beyond appearances. Twittering Machine 1922 (Museum of Modern Art, New York) is typical. Klee travelled with the painter August Macke to Tunisia 1914, a trip that transformed his sense of colour. His influential views on art were presented in Pedagogical Sketchbook 1925. The Klee Foundation, Berne, has a large collection of his work. Other publications include On Modern Art 1948. He studied at Munich under Franz Stuck and absorbed a variety of impressions from painters old and modern (Blake, Goya, Hans von Marees and Cezanne among them) before setting out - in his own words - to work "as one new-born". With Kandinsky, Marc, and Macke, he took part in founding the "Blaue Reiter" group 1912, taught at the Bauhaus 1921-31, and moved to the Deusseldorf Academy 1931. He moved to Bern 1933 when the Nazis came into power. A very large output in oil, watercolour, pen and pencil drawings and etchings reflects his independent and original imagination, his wit and charm of colour and line. In his theoretic study, Ueber die Moderne Kunst, 1945, he likens the transformation of life by the artist to the process by which the soil is converted into the foliage of the tree, and his own art illustrates this transformation, in human terms, through the subconscious. Klee, however, unlike the Surrealists, attached great importance to both observation and technique, as well as to more or less "automatic" processes of expression.