A deserted, half-derelict side street on the fringes of the City of London at lunchtime. The kind of unremarkable road people pass by every day without a second glance. But today, there's something different in the air. There's music coming from behind a closed door to an empty warehouse, beneath a Victorian railway arch. That arch is filled by a stage and musicians. And at the front is an impossibly thin, bearded man eating a chocolate bar and shaking some maracas. A band jams behind him. That man is the former Pulp frontman and, these days, the distinguished elder statesman of Britpop, Jarvis Cocker.
It's a spectacularly bizarre scene: cool kids in duffel coats and tight jeans slump on beanbags watching Cocker's band "rehearse". On the back wall, a man dips his paintbrush into a Dulux pot - he's not sprucing up the joint but painting a mural. Some are reading books. Others look up from laptops, not quite believing this is happening on a Monday afternoon. They're probably tweeting their good fortune at coming across Cocker for free, in an old warehouse, on a weekday.
But everyone else who's not tapping away on their keyboards looks nervous. And then I understand. A sign says that after the rehearsal, from 1pm to 2pm, it's "Bring An Instrument" time, a chance for anyone to get up and share the stage with Cocker. He finishes the rehearsal hour and goes to the microphone. He looks directly at me. I stop typing and gulp. The last time I played violin was 20 years ago, but there's definitely a spare one on stage, Thankfully, Cocker's long bony finger, infamous from videos such as Common People and Disco 2000, isn't pointing at me. Behind me an apprehensive man with an electric guitar on his lap gets up and sheepishly makes his way to the stage, plugs in, and starts jamming with a man who has sold more than 10 million records. Welcome to the weird and wonderful world of Jarvis Cocker. And more specifically, his new project: Jarvis Cocker Makes An Exhibition of Himself.
Despite the seemingly ad-hoc nature of it all, this "exhibition" has a point and a history. In October 2006, Cocker was asked to edit the British newspaper The Observer's monthly music magazine and asked the question "what is music for"? Two and a half years on, he shortened that to "what is music?". It was a response to the many articles he'd read at the time proclaiming the death of the music industry, as a result of illegal downloading. So he installed himself at Galerie Chappe in Paris for five days in May to try to find the answer.
"Does the death of the music industry mean that music can now go back to being an art form again?" he said before those dates. "What happens if you get a band to rehearse in an art gallery instead of a rehearsal space? What if you invite members of the public to play with the band? Or invite them to submit song titles which the band then have to base an improvisation upon. Could a live band provide the accompaniment to an aerobics class?"
It was a great success, which is why Cocker is repeating the experiment this week, culminating in a live gig tonight, where he might play something more akin to the pop songs people know him for. Sadly, there are no aerobics today - a shame, as I'd rather looked forward to laughing at 50 or so out of shape indie kids wheezing along to a fitness routine. There's no yoga as had been advertised, either, which slightly horrifies a flautist who has turned up.
"To be fired straight into a rock set was, er, slightly interesting," says a delighted Miho Wada from Lewisham just after her star turn. "My friends had told me to come down and mentioned the possibility of yoga, so I'd kind of prepared in my mind some meditative, calming music. The next thing I know, Jarvis is whispering in my ear: 'Right, you're starting this one' as he strapped on an electric guitar. So I had to go for it!
"I've always been a fan of Jarvis, and to play on the same stage as him was fantastic. He's so generous - in a way he's making everyone else the star rather than him." And Wada is a star - magnificent in a mournful 20-minute jam that breaks down for an extended handclap session and ends in blasts of white noise. So good, in fact, that I Google her later and learn she is, er, a professional flautist who has recorded with Iggy Pop. Still, this isn't a stitch-up - she genuinely did just turn up. And Cocker proves this by coming to the front of the stage again, this time, triangle in hand. "Anyone else with an instrument?" he says.
A hand is raised and a bass player is found. There is already a bass guitarist on stage, but it appears not to matter. "Come on, then," beckons Cocker. "Everybody, this is Joe." It's like The X Factor or Britain's Got Talent, but where everyone wins. And is talented. Of course, there's an irony in Cocker sharing stages: for a long time, he was best known for popping up uninvited during Michael Jackson's performance at the 1996 Brit Awards. But Cocker was at the Brits for a reason: Pulp were at their commercial peak. Their album Different Class was top of the charts and would go on to win the Mercury Prize. If Oasis and Blur were the slightly tiresome heavyweights slugging it out to be Britpop top dogs, Cocker's Pulp were the intelligent alternative. Common People, after all, is actually a song about how the British have an odd prediliction for glamourising poverty. As Cocker said at the time to Q magazine: 'I felt that [Blur's] Parklife, for example, has that noble savage notion. But if you walk round a council estate, there's plenty of savagery and not much nobility going on."
Cocker had earned the right to say such things: he'd grown up on a Sheffield council estate. Fame had been a long time coming - he formed Pulp in 1978 - and when he found it, he didn't much like it. There were drug problems, a hugely disappointing follow-up to Different Class, and, although they never officially split, there have been no more Pulp albums or gigs for seven years. Just by watching Cocker today, you can see why his current state of affairs suits him well. It means he can turn his attention to whatever he fancies. He presented a television series on outsider art and has collaborated with Nancy Sinatra, Marianne Faithfull and Charlotte Gainsbourg. He's appeared in Harry Potter and, more recently, Fantastic Mr Fox. He has a regular Sunday afternoon radio show beginning in January - typically tongue in cheek, he said that "he was going to put the boringness back into Sunday". And, of course, there have been two solo albums, the most recent of which, Further Complications, finds Cocker back on top musical form.
So, something of a star, then. But you'd never guess that from the way he ambles to the stage later in the afternoon and introduces the artwork being created on the back wall. "This is Charley from the Pure Evil gallery," he says. "And today it's the 20th anniversary of the fall of the Berlin Wall. Charley is creating a piece in response to that, and while he does, we're going to soundtrack it with music that has a Berlin feel."
Charley is poised. The band gets ready. And, obviously, the first lines of Pink Floyd's Another Brick in the Wall ring out across the increasingly cold space, to general guffaws. For the first time this afternoon, Cocker sings - "we don't need no education" in his unique Sheffield croon. Forty-five minutes later they're still at it, but miles away from where they began. And if attention has wandered slightly, that's because someone has brought out two poles for the 4pm Pole Dancing Workshop.
The flautist had come prepared for yoga. I had come prepared for aerobics. Neither of us had, in any strange corner of our minds, pictured a scene where we'd be invited to learn pole dancing while Jarvis Cocker's band played in the background. Of course, I am aware that such an activity is, these days, a legitimate fitness workout. But still, I prefer to hide in the shadows of the warehouse as the lithe instructor Lucy Misch asks for willing students.
And in the end, I feel a bit foolish for doing so. Not only do Misch's charges noticeably improve over the hour, but Cocker claps every single one of their moves. Again, he's made people who have come in off the street lose their inhibitions and become stars for a brief moment. Perhaps that's the point of Jarvis Cocker Makes An Exhibition of Himself. Certainly, you come away from a hugely entertaining afternoon thinking differently about him - and even music itself. Because, in the end, Cocker seems to be saying that music doesn't have to be about three minute pop songs downloaded in their millions. It doesn't even have to be performed by fame-crazed frontmen. It can, instead, be the soundtrack to whatever else is going on in our lives. Including yoga, aerobics, painting... and pole dancing.