The programmatic name Dada was chosen by a group of artists at random for their newly founded movement in 1916. Central figures in the Dada movement included Hans Arp, Hugo Ball, Richard Hülsenbeck, Marcel Janko and Tristan Tzara. They organised Dadaist performances, readings and concerts in the Cabaret Voltaire in Zurich. The public was not infrequently shocked, and before long the complaints caused the nightclub to close its doors. What united the Dada artists was their protest against the horrors of the First World War. Using mockery, irony and nonsense they turned in a radical and provocative manner against bourgeois society and the pathos of its values, which they considered hollow. They developed innovative artistic forms such as the sound poem, for example, in which they broke up linguistic clichés in the form of vowels and consonants and then put them back together again according to the principles of a collage. The members of the Dada movement propagated an anti-art and had recourse to unusual materials such as lost-and-found objects or refuse, which they integrated into their works in a collage-like manner. Chance also became a central design element, together with disorder. Many works confronted seriousness with triviality or transformed declarations and meaningfulness into their exact opposite. An independent Dada movement also developed in New York around Marcel Duchamp, Man Ray and Francis Picabia. Other centres of the international movement were Paris with André Breton and Céline Arnauld, Berlin with Hannah Höch, Raoul Hausmann and Johannes Baader, Hanover with Kurt Schwitters, Dresden with Otto Dix and Otto Griebel and Cologne with Max Ernst and Johannes Theodor Baargeld.