Dubstep is everywhere – and if you will excuse a little self-promotion I have, in my small way, helped this state of affairs come about. The bass-heavy, rhythmically exploratory and very British electronic dance music genre has now – via Magnetic Man and Katy B – proved it can produce bona fide top-10 hits, and it has become the de facto sound of every summer festival to boot, while still keeping both feet in the underground clubs from whence it emerged.

Tulisa, Dappy and Fazer of North London pop phenomenon N-Dubz – or, if you prefer, Tula Constavlos, her cousin Dino Constavlos and their schoolfriend Richard Rawson – are easy to mock, and Channel 4 know it. The first episode of this showbiz slice-of-life documentary about the ebullient trio is so slathered with the kind of hideously knowing upper-middle-class arched-eybrow voiceover that characterises the whole of the channel's T4 youth programming strand that you have to wonder if they actually credit the viewer with the ability to form an opinion at all.

Today Rinse FM, London's leading pirate radio station, announced it has been granted a legal broadcast licence after 16 years of illicit transmissions. It's almost impossible to overstate how potentially momentous this event is for the UK's most vibrant and promising music scenes, and what opportunities it presents for artists, personalities and record labels ranging from the deep and experimental to the most flagrantly commercial. From the rumbustuous, teen-friendly fun of Scratcha's breakfast show to the experimental electronic jazz and funk of Alex Nut at Saturday lunchtime to various hard and dark grime and dubstep shows - as often as not playing exclusive music fresh from the hard drives of its creators that may never even become commercially available - it is a brilliant representation of London's cultural vitality in the 21st century.

A little revolution is taking place at the top of the pop charts. UK artist Tinie Tempah's rap track “Pass Out” has had two weeks at number one, and at the time of writing looks very much like it may successfully fight off Lady Gaga & Beyonce's spectacularly-hyped “Telephone Thing” to make it a third week on top.

Amongst all the musical benefits for the victims of the Haiti earthquake, one club event which took place on Wednesday night in London stands out as a small, but powerful, beacon of hope. Not because it could rival Jay Z and U2 for levels of funds raised, but because it represented levels of commitment, self-motivation and unity among the capital's multi-ethnic youth subcultures that flies in the face of scare stories about gang violence, drugs, educational failure and all the rest of it. Raising well over £10,000 for Haitians, the entire event on Wednesday night at the club Den/Centro was pulled together in a mere three days by journalist and activist Chantelle Fiddy, promoters SOMEnight, and DJ Stanza of the Watford-based dubstep and grime label True Tiger, and went without hitch despite featuring on its diverse bill many grime rappers and DJs who find it difficult to perform in London due to police pressure on promoters. theartsdesk spoke to a dazed but happy Chantelle Fiddy yesterday to discuss the ramifications of the event.

The received opinion is that the music of the 2000s has been characterised by fragmentation, discontinuity, faddishness and a lack of coherent identity.