Video: SBTV appears in a Google Chrome advert By his own admission, Jamal Edwards was not a model pupil. At school he was disruptive, easily bored and, like many teenage boys growing up on west London’s hard-knock council estates, he got into fights.

One despairing teacher told him he would never achieve anything unless he knuckled down. But as far as Jamal was concerned, he already was — just not academically. In his spare time he would film his friends rapping — “spitting”, they called it — on his mobile phone and post the results online. Soon, half the school was tuning in.

Six years on, at 21, Jamal is still hard at work. Only now nobody can deny his success. His online TV station, SB.TV, has had over 74m hits and is turning over six figures. He may soon be worth much more. This summer, he starred in a TV ad for Google Chrome, made by the advertising giant BBH.

He recently spent the day with Sir Richard Branson, “one of my inspirations”, to seek advice on how to turn his fast-rising business into an empire; he hopes to collaborate with the Virgin boss soon. At parties he rubs shoulders with Beyoncé, Gwyneth Paltrow and Sir Philip Green. Such celebrity gloss is a world away from SB.TV’s gritty core content — which, more often than not, depicts life closer to the bottom of society than the top.

The lyrics can be brutal, an oral history of Broken Britain. It’s the voice of youth

Grime is Britain’s answer to hip-hop. A music that evolved on inner-city council estates, hidden away from mainstream society, before emerging to rival Simon Cowell’s televised bear-baiting as the biggest source of new British talent.

Many of today’s chart-toppers — Dizzee Rascal, Plan B, Tinchy Stryder, Chipmunk and (Prince William’s favourite) Tinie Tempah — began their careers making grime. Most are still in their early to mid-twenties. And now a new, even younger generation is making grime pay, too.

Grime began on London’s underground club scene and pirate-radio stations.

There was a trend for DJs to play sparse electronic instrumentals — not much more than a beat, handclaps, bass line — over which MCs taking turns with a microphone would “spit” lyrics. At first these were simple party slogans to encourage people to dance, delivered in a slangy argot pitched somewhere between the cockney East End, west Africa and the Caribbean. As the music was twice the speed of hip-hop, the MCs had to practically spit their words out to keep up.

The first grime MC to impact on the public consciousness was Dizzee Rascal in 2003.

Seen as an anomaly at the time, his big break came aged 19 when he beat the likes of Radiohead and Coldplay to win the Mercury Music Prize for his debut album, Boy in da Corner. The lyrics were angry, angsty social commentary. To anyone who heard the bleak, frequently violent account of underclass life on Dizzee’s album, the only surprise about this summer’s riots was that they took so long to happen.

SB.TV, too, offers vitality and controversy. Much of its content focuses on MCs filmed on the street, or in their estates, showboating their street-poetry skills. This kind of delivery is known as “freestyle”: the music is added in the edit before broadcast. The grime MCs can thrill with their rapid-fire wordplay, there is wit and wisdom, but the lyrics can be brutal too, an oral history of Broken Britain.