Question: Otto Muehl was a main participant in what short and violent 20th-century art movement?

Context paragraphs:
20th-century art: 20th-century art—and what it became as modern art—began with modernism in the late 19th century.  Nineteenth-century movements of Post-Impressionism (Les Nabis), Art Nouveau and Symbolism led to the first twentieth-century art movements of Fauvism in France and Die Brücke ("The Bridge") in Germany.  Fauvism in Paris introduced heightened non-representational colour into figurative painting.  Die Brücke strove for emotional Expressionism.  Another German group was Der Blaue Reiter ("The Blue Rider"), led by Kandinsky in Munich, who associated the "blue rider" image with a spiritual non-figurative mystical art of the future.  Kandinsky, Kupka, R. Delaunay and Picabia were pioneers of abstract (or non-representational) art.  Cubism, generated by Picasso, Braque, Metzinger, Gleizes and others rejected the plastic norms of the Renaissance by introducing multiple perspectives into a two-dimensional image.  Futurism incorporated the depiction of movement and machine age imagery.  Dadaism, with its most notable exponents, Marcel Duchamp, who rejected conventional art styles altogether by exhibiting found objects, notably a urinal, and too Francis Picabia, with his "Portraits Mécaniques".

Concrete art: Concrete art is an art movement with a strong emphasis on abstraction.  The artist Theo van Doesburg, closely associated with the De Stijl art movement, coined the term "concrete art" as he in 1930 founded the group Art Concret and articulated its features in a manifesto titled "The Basis of Concrete Art", signed by four other artists of the group, including Otto G. Carlsund, Jean Hélion and Leon Tutundjian.  The manifesto explained that the resultant art should be non-referential insofar as its components should "not" refer to, or allude to, the entities normally encountered in the natural, visible world.  This is a distinction from abstraction generally.  In a more general sense "abstract art" could and often does include the "abstraction of forms in nature".  But "concrete art" was intended to emanate "directly from the mind" and consequently to be more "cerebral" than abstract art generally.  Concrete art is often composed of basic visual features such as planes, colors, and forms.  "Sentiment" tends to be absent from concrete art.  The "hand" of the artist may be difficult to detect in finished works of concrete art; concrete art may appear, in some instances, to have been made by a machine.  Concrete art often has a core visual reference to geometry whereas more general abstract art may find its basis in the components of the natural world.  A formulation of a description of concrete art might include a considerable reliance on the formal qualities of an artwork.  Theo Van Doesburg's manifesto stated that art "should receive nothing from nature's formal properties or from sensuality or sentimentality.  We want to exclude lyricism, dramaticism, symbolism, etc…."  In concrete art a mathematical equation can serve as a starting point.  Concrete art can include painting and sculpture.

Futurism (music): Futurism was an early 20th-century art movement which encompassed painting, sculpture, poetry, theatre, music, architecture and gastronomy.  Filippo Tommaso Marinetti initiated the movement with his "Manifesto of Futurism", published in February 1909.  Futurist music rejected tradition and introduced experimental sounds inspired by machinery, and influenced several 20th-century composers.

Aktionsanalytische Organisation: The Aktionsanalytische Organisation (AAO), commonly known as the Friedrichshof Commune, was an Austrian far-left commune in Friedrichshof outside Vienna and authoritarian sect (described as a "psycho sect" by authors Nordhausen and Billerbeck) that was founded by Otto Muehl in 1972 and dissolved in 1990.  Muehl was subsequently convicted of widespread sexual abuse of minors who lived in the commune and sentenced to 7 years in prison.

Otto Muehl: Otto Muehl (16 June 1925 – 26 May 2013) was an Austrian artist, who was known as one of the co-founders as well as a main participant of Viennese Actionism and for founding the Friedrichshof Commune.

Lisa Wainwright: Lisa Wainwright (born September 1960) is an American art historian, the Vice President of Academic Affairs, and Dean of Faculty, at the School of the Art Institute of Chicago (Summer 2010 – present) and the Title IX officer for SAIC for faculty.  Wainwright received a Ph.D. in the history of 19th and 20th-century art, University of Illinois, 1993; an M.A. in history of 19th and 20th-century art, University of Illinois, December 1986, and a B.A. cum laude, Vanderbilt University, art history, June 1982.  She also studied at the Goethe-Institut in Blaubeuren, Germany, in summer 1982.

Viennese Actionism: Viennese Actionism was a short and violent movement in 20th-century art.  It can be regarded as part of the many independent efforts of the 1960s to develop "performance art" (Fluxus, happening, action painting, body art, etc.).  Its main participants were Günter Brus, Otto Mühl, Hermann Nitsch, and Rudolf Schwarzkogler.  As "actionists", they were active between 1960 and 1971.  Most have continued their artistic work independently from the early 1970s onwards.

Scuola Romana: Scuola romana or Scuola di via Cavour was a 20th-century art movement defined by a group of painters within Expressionism and active in Rome between 1928 and 1945, and with a second phase in the mid-1950s.

Impressionism: Impressionism is a 19th-century art movement characterized by relatively small, thin, yet visible brush strokes, open composition, emphasis on accurate depiction of light in its changing qualities (often accentuating the effects of the passage of time), ordinary subject matter, inclusion of "movement" as a crucial element of human perception and experience, and unusual visual angles.  Impressionism originated with a group of Paris-based artists whose independent exhibitions brought them to prominence during the 1870s and 1880s.

Idyllic school: The Idyllic school (also known as the Idyllists) was a 19th-century art movement of British artists—both painters and illustrators—whose depictions of rural landscapes combined elements of social realism and idealism.  Van Gogh admiration for the group was shown in letters to his brother Theo.  Nowadays the Idyllist school is seen as one of the earliest manifestation of the social realism movement in art

Supporting paragraphs: Otto Muehl Viennese Actionism
Answer: Viennese Actionism