In 1974, one of America's most celebrated cultural figures declared graffiti as "the great art of the 70s".
Back then, thousands of teenagers were vandalising New York, in particular the subway system. Yet Norman Mailer described their "passion", their "cool", their "masterpieces in letters six feet high".
Who were the teens behind the "tags", now the veterans of the scene? Why did they create this movement? Were they even thinking about art, politics, protest... or simply writing their names on trains?
BBC Radio 4 meets some of those who defied the law (and their parents) and diced with death. These include pioneers such as Riff 170, Jester, Coco 144, Flint Gennari, and Tats Cru. Their efforts have been replicated far beyond New York - into art galleries, and into the hands of Arab Spring protesters - and yet their aspirations were largely apolitical: they were chasing fame, and the acceptance of their peers.
The programme explores the city's complicated relationship with graffiti, which it appears to condemn and celebrate in equal measure. Former artists - or "writers", as they prefer to be known - revisit their old haunts, and discuss why they believe they had a right to "tag", "bomb" and "destroy" New York with markers and spray paint.
The programme paints a vivid picture of a city that became a canvas at a time when, according to Norman Mailer, "it looked as if graffiti would take over the world".
"If names such as Riff 170, Jester and Coco 144 mean nothing to you, don’t worry — this superb production provides a window on their world, with a soul, funk and hip-hop soundtrack that throbs to the beat of the New York streets." - Radio Times, August 2014
"A silky mix of wonderful sound design, and great music" - Chris Watson, Pick of the Week, 10th August 2014
First broadcast on 7th August 2014 BBC Radio 4
Produced by Steve Urquhart