hatever you think of street art, there’s no denying its pedigree. The paintings done on cave walls 30,000 years ago are today acknowledged as the first creative triumph of the human mind. But before their modern recognition as prehistoric wonders, these pictures of mammoths and bison were dismissed by Renaissance cavers who came across them as crude contemporary graffiti. That’s because graffiti were as universal 400 years ago as they are today, and just as disreputable. Today we veer between seeing graffiti as visual noise and genius coming up from the streets. That’s the fascinating ambiguity of those marks and images. They can be dismissed as a public nuisance or hailed as works of witty artistic genius. Banksy in Britain and JR in France have followed in the footsteps of the 1980s New York street and subway art stars Jean-Michel Basquiat and Keith Haring to become respected and marketable. Basquiat and Haring were proteges of Andy Warhol, whose embrace of high and pop art, the beautiful and mundane, set the stage for today’s street art. Warhol himself responded to the graffiti craze with a series of abstract paintings he made by covering the canvases with copper, then urinating on them to oxidise the pigment and produce lovely mineral blues and greens. It was literally the lowest of street activities, peeing against a wall, become Art. This may sound an uncharacteristically macho activity for Warhol – it’s clearly a piss-take take of Jackson Pollock’s drip method. Street art has always had a masculine quality. Even in Dutch 17th-century art it’s boys, not girls, who are depicted drawing on walls. Warhol pissing on canvases, with all his grave irony, stayed closer to the base origins of street art than a lot of today’s street art does. Banksy is not just the modern genre’s biggest star but carries the blame for making it respectable – maybe too respectable. He raised the art of the street from inchoate irrational marks to pointed political interventions. Yet the more satirical or eloquent street art becomes, the less it resembles great art. For the discovery of street art’s genius in the 20th century, at the same time that cave art was finally appreciated, was part of a modernist cult of the untamed. The surrealist movement found poetry in the streets and the surrealist photographer Brassai photographed strange demonic graffiti etched on Parisian walls. Pollock brought that gutter energy to high art when he danced around flinging paint to the sound of jazz. Meanwhile the French artist Jean Dubuffet championed art brut, raw or outsider art including graffiti. Cy Twombly mixed it up further, adding scribbled writing to his abstract canvases as well as crude street art images of penises, anuses and vaginas. Twombly embraces the chaos of street marks in a lush, sensual sigh of colour that is dirty and grand. Most street art you see is as mysterious, unkempt and unassimilable as the scribbles that inspired these modernists – but that’s not the stuff we tend to pick out as art. This is the age of the message. It’s all about what the artist is “saying”. Murals with messages that we applaud get retweeted with pride. Right now we’re in a war with a virus and the street art of the pandemic serves a communal purpose. But great art, in the gallery or on the street, is stranger and more enigmatic. The next great street artist is more likely to be doing rude drawings in a public loo than painting inspiring messages.