Street art that we share online tends to be inspiring – not strange, enigmatic or challenging

Whatever 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.