On a barren plain close to Kenya's Lake Baringo, Nehemiah Toromer sits precariously on a rickety green chair outside the crumbling mud structure that he calls home. His paralysed legs are unable to support him and his left arm lies limp and useless in his lap, yet with tears in his eyes he raises his right fist to the sky and in a voice breaking with emotion shouts out: "God is great."
Yet Toromer has little to be thankful for. As he unsuccessfully fights to hold his tears at bay, he explains how raiders had come in the night and robbed the livestock that provided his livelihood. The trauma, still visible in his eyes, shocked the life out of much of his body. He says he is 55 but his grey hair and withered frame suggest a septuagenarian. With a wife, adult daughter and several small children dependent on him, only his faith keeps his despair at bay.
Crouched before Toromer is an unlikely goatee-bearded figure in a San Francisco Giants baseball cap and a chequered shirt bearing the insignia of Rocawear, the clothing label founded by Hip Hop mogul Jay-Z. He is Josh Davis, 34, otherwise known as DJ Shadow, here on his first visit to Africa. Two days previously, the acclaimed Californian turntableist said goodbye to his twin baby daughters at his home near the Golden Gate Bridge and flew 10,000 miles to find himself suddenly confronted with the devastating effects of chronic poverty, scarce natural resources, a plague of firearms and an unforgiving climate.
DJ Shadow has an aptitude for chemistry in the recording studio that has won him international admiration; he is not known for solving economic, environmental and geo-political problems in the developing world. "It's hard to drop in out of the sky and say, 'We are going to make a world of difference in your life,'" he acknowledges later as he reflects on the encounter with Toromer. "On an empathetic level it was hard to relate to him. It's not like that's ever happened to me, thank goodness, and it's hard to be aware of the gravitas of what's happened to him."
Yet Toromer's indefatigable spirit persuaded Shadow that he must help. "When he said 'God is great' I was so surprised because he seemed so desperate. It was nice to hear that note of optimism and I just don't think I can walk away from stuff like that."
Oxfam certainly believes Shadow can make a difference. In October it will stage Oxjam, its most-ambitious music project to date, a UK-wide series of fund-raising gigs, club nights and buskathons. DJ Shadow, with his wide appeal to the twenty- and thirty-somethings who would be fundamental to Oxjam's success, can be an influential apostle.
Toromer can already see the value of Oxfam's work. Herded into a small corral fashioned from thorn bushes are a fresh stock of 10 goats, given to the stricken man by the elders of nearby Meisori village, who decided he was a worthy beneficiary of an Oxfam programme aimed at minimising the devastation caused by armed gangs of animal rustlers. A practice referred to in John le Carré's Kenya-set novel The Constant Gardener as "the local sport", rustling has become a murderous business with the growing availability of Armalites and Kalashnikovs from conflicts in neighbouring countries.
After a bone-shaking five-hour drive from Nairobi, Shadow emerges from an old Toyota Land Cruiser to be greeted by a swarm of schoolchildren in matching mauve cotton dresses and shirts. The DJ is led into a barely furnished classroom where the words "Be Responsible & Hardworking" have been daubed in paint above the blackboard. He is told how three tribes in this western Kenyan region - the Pokot, the Tugen and the Ilchemus - have formed "peace clubs" to tackle animal thieving, even though the children are still scared of the raiding parties.
Outside on the hard earth of the school play area, the children, mostly wearing adult sandals made of cheap, brightly-coloured plastic, perform a skilfully choreographed song and dance routine for Shadow. He sits before them at a wooden table, a not-entirely-comfortable guest of honour. "At one point the kids were laughing at what was being mimed," he says. "I smiled until I was told they were showing a mother unable to physically carry both of her children away from a conflict zone. I immediately stopped smiling. Looking at the children's faces again, you see there's a lot of sorrow and hardship there."
As raindrops start falling like ball-bearings, three travelling Maasai performers take their turn to pogo and triple-jump, their sweet falsetto singing backed by a makeshift guitar crafted from a United Nations oil can. Shadow is impressed. "I really appreciate it when people take the rubble around them and make something of it. That's essentially how rap began, from the devastation in New York in the Seventies. I like the idea of taking an oil can off the ground, tying some string around it and making an instrument. That's what we were listening to and it was gorgeous." One of the Maasai, David Olenaso, shows an entrepreneurship that Def Jam founder Russell Simmons would admire, selling copies of his music, handing out his mobile phone number for bookings and pulling the handset from the waistband of his red skirt to take a call.
Another long drive brings Shadow to a village hall in Kapenguria, where tribal dancers from the Marakwet and Pokot in beaded necklaces and faces dotted with white paint perform in his honour. Though he conducts himself with courtesy and humility, Shadow is a little uneasy in the role. "You have this negative image of these men that might sit there saying 'Entertain me, regale me with your stories and songs!'" he says. "I wasn't quite sure what to say or do other than minimise any sense that I was better than anybody else. I am humbled in the presence of these people that have very, very little and yet have this incredible spirit. You could summarise it by saying it's a form of Western guilt."
Mobile phone technology is spreading in the remotest parts of Kenya, but firearms are hardly less difficult to come by. A drama performance ends with the dancers surrendering their "guns" (sculpted from succulent plants), a symbolic acknowledgement of the way firearms have undermined their traditional way of life. Shadow is brought onto the stage and garlanded with his own necklace, made from grass, a sign of peace. "Thank you for taking the time to educate me, now I can be a teacher," he tells the audience.
Later, he speaks of how the drama "really drove home to me" the plight of the people he met. "Everybody is fighting over resources and this has been going on for a very long time. But as soon as guns entered the scenario the fear factor and tension in the area has multiplied exponentially," he says. "When I stood on stage, I said that I understood this wasn't just fun and games and there's a message that needs to be related to outside."
The following morning, Shadow is driven back to Nairobi through the verdure of the Rift Valley, the setting for the film White Mischief, which portrayed the louche living of British colonialists in what was known in the Thirties as "Happy Valley".
By contrast, the brutal urban poverty of Nairobi is shocking to the American. Described as "a vast brown smear of smoking tin houses overhung with a pall of sickly African dust" in The Constant Gardener, Nairobi's slums are home to several million people, 48 per cent of whom test positive for HIV. Life expectancy has tumbled from 60 to 40 in the space of 15 years. The drains of the Babadogo slum are not even open trenches, but typically a shallow groove in a muddy street that allows a noxious stream of waste to trickle downhill.
Yet beneath the blue tarpaulin that shelters the small concrete auditorium of the grandly titled African Cultural Research and Educational Foundation (ACREF), the local youth are determined to make themselves heard. Their spirit is typified by The Lucky Summer Youth Group, 25 young men who earn pennies gathering rubbish from their neighbourhood, where waste disposal services are unknown. Another group, Myto, uses the traditional orutu D-shaped instrument to implore listeners to take malaria vaccinations. Shadow praises the music. "I felt more comfortable in the slum because I think I can relate to that mind-state more than I could the ultra-rural environment, where there were cultural and tribal influences at work and I wasn't sure if I was going to do or say the wrong thing," he adds.
The audience at ACREF howls for Shadow to DJ, but technical complications limit his performance to an uptown party later that evening hosted by Kenyan musician Eric Wainaina. "I wish I could have done it in the slums," says Shadow.
Seeing young Kenyan artists - and discovering in Nairobi record stores a sackful of dusty Seventies African vinyl - has fired his imagination. "It's good to remind myself of the purity of intent of the people that performed. Obviously it wasn't a money thing. It was like the book title I Know Why the Caged Bird Sings."
He returns to America pledging that, through Oxfam, he will try his best to make a difference. "You cannot just get overwhelmed with this poverty and say 'Anything we do is just a drop in the bucket'," he says. "You have to start somewhere."
Oxjam takes place across the UK throughout October. For details visit www.oxfam.org.uk/oxjam DJ Shadow performs at London's O2 Arena, 19 July