Art bienniales are held in Dakar, Senegal, and Johannesburg, South Africa. Many contemporary African artists are represented in museum collections, and their art may sell for high prices at art auctions. Despite this, many contemporary African artists tend to have a difficult time finding a market for their work. Many contemporary African arts borrow heavily from traditional predecessors. Ironically, this emphasis on abstraction is seen by Westerners as an imitation of European and American Cubist and totemic artists, such as Pablo Picasso, Amedeo Modigliani and Henri Matisse, who, in the early twentieth century, were heavily influenced by traditional African art. This period was critical to the evolution of Western modernism in visual arts, symbolized by Picasso's breakthrough painting Les Demoiselles d'Avignon. Today Fathi Hassan is considered a major early representative of contemporary black African art. Contemporary African art was pioneered in the 1950s and 1960s in South Africa by artists like Irma Stern, Cyril Fradan, Walter Battiss and through galleries like the Goodman Gallery in Johannesburg. More recently European galleries like the October Gallery in London and collectors such as Jean Pigozzi, Artur Walther and Gianni Baiocchi in Rome have helped expand the interest in the subject. Numerous exhibitions at the Museum for African Art in New York and the African Pavilion at the 2007 Venice Biennale, which showcased the Sindika Dokolo African Collection of Contemporary Art, have gone a long way to countering many of the myths and prejudices that haunt Contemporary African Art. The appointment of Nigerian Okwui Enwezor as artistic director of Documenta 11 and his African-centred vision of art propelled the careers of countless African artists onto the international stage. A wide range of more-or-less traditional forms of art, or adaptations of traditional style to contemporary taste are made for sale to tourists and others, including so-called "airport art". A number of vigorous popular traditions assimilate Western influences into African styles such as the elaborate fantasy coffins of Southern Ghana, made in a variety of different shapes which represent the occupations or interests of the deceased or elevate their status. The Ga believe that an elaborate funeral will benefit the status of their loved ones in the after-life, so families often spare no expense when deciding which coffin they want for their relatives. These coffins can take the forms of cars, cocoa pods, chickens, or any other shape a family may decide best represents their deceased