This month marks a hundred years since the artist Marcel Duchamp submitted his now famous artwork, Fountain, to an international exhibition in New York. Influenced by Dadaism his submission was simply a urinal he’d bought in a local shop. Duchamp’s surrealist questioning of institutional definitions of art has had a defining impact on modern art. Now, rather then creating something, a contemporary artist will add the label ‘art’ (and therefore implicit meaning) to anything they choose. Duchamp’s legacy has left a large portion of the public completely baffled when they enter a contemporary art gallery. Alongside its increasing commodification and institutionalisation this pretentiousness has also crept into urban art. This is what leads Pietro Rivasi, writing at the start of Trains, Travels & Murals, to declare that “we are living in the dark, medieval times of urban art.”