The open spaces of Hackney Marshes normally play host to 82 full-sized football pitches and innumerable Sunday league kickabouts. Club scouts roam the fields, theoretically incognito.
This weekend, the shouts and referees' whistles have been replaced by the sound of reverberating bass, as a Premier League of urban pop talent – the likes of Jay-Z and Rihanna – sets up camp along east London's river Lea. Past the fluttering flags and over the high security fence lies the Lea itself, a river system often as polluted as the Ganges, according to a body set up to safeguard it, Love The Lea
For a tiny water course, its flow is charged with significance – the Olympic Park is just downstream and the Lea connects the marshes with the road in Tottenham Hale where the shooting of Mark Duggan by police sparked widespread rioting last year.
Radio 1's Hackney Weekend is being billed as the station's largest-ever roadshow, a free 48-hour event set across five stages. By Sunday night's 10.30pm curfew, it will have been witnessed by an audience of 100,000. The star quality is high. On Saturday, if you were quick, you could catch the hits of a trio of major female UK stars. Kosovan-born west Londoner Rita Ora played the first No 1 single of the day, at exactly 14.07, Hot Right Now, in a heaving In New Music We Trust tent. On the main stage, local girl Leona Lewis was singing Bleeding Love. Over in Radio 1Xtra's tent, Emeli Sandé was packing them in.
The first shivers of the day didn't just come courtesy of the piercing wind but the multi-ethnic, age-blind Hackney Empire Community Choir, backing Lewis up on Run'. Later on, she was joined by rapper Wretch 32, from just up the river in south Tottenham.
Radio 1 events have not always been like this. Following on from the now-quaint roadshows of the 80s, when Radio 1 DJs rocked up in out-of-the-way towns to play records in public, the 90s witnessed the introduction of live bands. In 1992, Del Amitri, Aswad, the Farm and Status Quo rocked Birmingham in the service of the BBC's youth station.
By contrast, last year's Big Weekend in Carlisle played host to Lady Gaga. This year, US stars Jay-Z and Rihanna top a lineup in which hip-hop and R&B feature heavily. After decades in which UK urban music was the poorer relation of its hegemonic US cousin, the crowd is clearly here to see homegrown stars as much as glamorous imports such as female rapper Nicki Minaj, another of the evening's major attractions.
As the day progresses, though, rock acts become more of a focal point. Indie-rock white hopes the Maccabees give way to the Vaccines, and grinding hips give way to pogoing. There is an especially loud spot to the left of the main stage where, if the wind is right, the punchy bluster of Kasabian – probably the biggest British rock band of the moment – does battle with the frantic drama of Wales's Lostprophets. Best of all is INMWT headliner Jack White, playing tonight with his all-male band (he tours with two outfits, one all-female). His hat is low over his eyes; his lighting is an intense blue. While most acts are just satisfied to play their songs, White urges his extraordinary band on to extended jams before making his way over to the main stage to watch headliner Jay-Z from the side of the stage. Most festivals boast large screens either side of their main stages. Here, there are screens outside the tents too, ensuring the overspill of fans doesn't miss out – a civilised novelty befitting a large media organisation.
A small stage has been given over to new talent from the local Olympic boroughs, in which pop-grime – east London's permutation of commercial hip-hop – alternates with young R&B singers. In keeping with the UK hip-hop tradition, in which endearing names dominate (Dizzee Rascal, Tinchy Stryder, Chipmunk), Cheekie Bugga ought to have a future.
The idea to site 2012's Weekender in Hackney emerged from a sense that local young people felt left out of the Olympics. "Here at Radio 1 and 1Xtra we wanted to make sure that we marked this in a way that would give young people from London and beyond, who might not necessarily be engaged with the Games, a chance to celebrate as part of Festival 2012," explained BBC Radio 1 controller Ben Cooper in a blog earlier this week.
The Hackney Weekend has been criticised by veteran festival promoter Vince Power, former prime mover of the Reading festival, and now running Hop Farm and Benicàssim in Spain. Complaining that taxpayers' money should not be spent on a free festival in times of austerity, he went on to say: "If the BBC is giving something out for free, then we can't compete. It's really pissed me off."
Cooper hit back: "We're going into an area that I don't think any commercial operator would have gone into after the unrest of last year. That is the job of the BBC." This might come as a surprise to the organisers of Field Day and the Lovebox Weekender, who have both run successful events in Victoria Park, E5, earlier this month.
Encouragingly, though, the station has not just parachuted in a festival. For the past month, Radio 1 has been running an academy of workshops, masterclasses and talks in Hackney's new cinema, where east London success stories – Lewis, Plan B, Dizzee Rascal and Dragon's Den alumnus Levi Roots, among others – have been working with local young creatives in an effort to equip them with skills to confound society's expectations of riot-stricken youth.
Their T-shirt designs are on sale alongside the official merchandise. The Heatwave – a soundsystem playing bashment, a variant on dancehall reggae – perform an afternoon set near the avenue of food outlets. And although the BBC logo is ever-present – you can even climb up on a giant B or C cube and have your picture taken – there are little semi-official enclaves as you might find at Glastonbury.
The young and the even younger are out in force. Jenny, 26, and Kate, 25, are lolloping across the field towards Example's set on the main stage. "We love Example," Kate enthuses, before adding "but we're excited about Jay-Z." "And Kasabian!" Jenny interjects. "And Kasabian," she grins.
Twelve-year-old Sasha and her brother Nyan, nine, from Luton, are here with a female relative. "We want to see Rita Ora," they agree. They do not seem disconcerted to be told she's already been on. "Nicki Minaj too," adds Sasha. Their chaperone is thrilled to have brought them. "They're a bit young for festivals, but they love music, and I'd take them to this as a kind of induction to festivals."
The dance tent attracts a committed crowd, for whom other attractions – food, drink, daylight – hold little interest. Canadian electronic musician deadmau5 comes on wearing his customary giant mouse head, which he eventually removes to wild cheers. Rizzle Kicks close their good-natured set of old school melodic hip-hop with Down With The Trumpets, a sunny moment defying the overcast chill.
As the afternoon gives way to evening, there is a revelation in the BBC Radio 1Xtra tent. It's not the latest rapper, however. Singer and band leader D'Banj is introduced as "the Nigerian answer to Michael Jackson", and proceeds to unleash Afrobeat party music on to the marshes. It's not just Hackney's sizable Nigerian population singing along, though. D'Banj's recent breakout tune, Oliver Twist, is a singalong for all. On the main stage, rapper Nicki Minaj, all Rapunzel tresses and bondage bodysuit, alternates between her hardcore raps (rudest words left out) and more anodyne pop hits.
More amusing is the discovery that – even in 2012 – people still turn up in their numbers to watch DJs play records. The R1 DJ stage is perhaps the loudest stage here, drawing a crowd of a few hundred, many brandishing miniature vuvuzelas branded with Radio 1 hip-hop DJ Tim Westwood's name.
A much-rumoured appearance by Cheryl (formerly Cole) fails to materialise during Calvin Harris's set. Headliner Jay-Z, however, plays host to a veritable crowd of stars. Sunday's headliner Rihanna makes a swift appearance at the start of the set, followed by MIA, who performs her hit Paper Planes to a delirious crowd. Her microphone then packs up.
With hits such as 99 Problems and Empire State of Mind, Jay-Z – a drug dealer-turned-rapper-turned-mogul – doesn't really need much help to close a festival. But the last third of his set finds him joined by Kanye West, his former beatmaker-turned-pop star, with whom he has recently toured as Watch the Throne. Performing a bravura set of hip-hop duets that take in politics, philosophy and plenty of sex, they close with Niggas in Paris, watched by Jay-Z's wife Beyoncé, moshing in the photographers' pit. The threatened rain lashes down, but few mind.
The view on Twitter
Great crowd #R1Hackney instagr.am/p/MPKv2dyMl4/
— Tim Westwood (@TimWestwood) June 24, 2012
@TimWestwood: D'Banj smashed it today #R1Hackney big up all Nigerians instagr.am/p/MPI92cSMkV/ @iamdbanj
— D'banj kokomaster(@iamdbanj) June 24, 2012
Hackney....WTF!!!!!! Never seen bouncing like that!!!!!!!!!!!!
— Swedish House Mafia (@swedishousemfia) June 23, 2012
Beyoncè raving it up at #R1Hackney..instagr.am/p/MO_BI_gb4r/
— Jamal Edwards(@jamaledwards) June 23, 2012
— Beyonce Knowles (@Beyonce__Knowle) June 24, 2012