On YouTube, you can see and hear The Sound of Kuduro, Buraka Som Sistema's video for their breakthrough single. It cost €50 to make, plus the expense of travelling to Angola, the home of kuduro, the latest ghetto-funk rhythm to circle the world.

It shows Angolans body-popping and back-flipping to a sparse, urgent electronic sound, revved up by MCs including MIA. One million views later, and the sound had arrived.

Buraka Som Sistema (Portuguese for Buraka Sound System, Buraka being a Lisbon suburb) are in the video – producers Joao Barbosa and Rui Pite, DJ/producer Andro Carvalho and Angolan MC Kalaf. Since its making, they've worked with Damon Albarn's Africa Express, Hot Chip, Sway and Kano, the latter on their exhilarating debut LP, Black Diamond.

All but Carvalho meet me to explain kuduro and how they twisted it. "Kuduro was never world music," Pite says. "It was Angolan kids trying to make techno." Kalaf says: "Back in 1996, when I left Angola, kuduro was closer to techno or house. And when I moved to Lisbon, things kept evolving. Kuduro started as a dance, then DJs, now it's the MC era. The beats are less crazy. But of course, the MCs are crazier and crazier...."

Barbosa and Pite were high-school friends in Amadora, a Lisbon suburb. "It's where every Angolan ends up living," Barbosa says. Kalaf came to the city to study, continuing post-colonial connections as Angola and Mozambique's independence was entwined with the 1974 overthrow of Portugal's own dictatorship. "When we got freedom, so did Portugal," he says. "That brings us together."

Portugal forged their sound in other ways. "It's different from Latin countries like Spain and Italy," says Barbosa. "Lisbon's almost as up to date as London. Growing up there gave us a good education in all the strange, underground stuff. I went into the first drum and bass club in Lisbon in 1996 – Spain didn't get it till 2004. We kept following dance culture."

Kalaf was a spoken-word artist when he met Barbosa and Pite. Eager to put their love of kuduro into practice, they booked Buraka Som Sistema into an unsuspecting local club. "The best moments of DJing for me were at the beginning," says Barbosa. "We played this tiny club in Lisbon, for four nights in 2006. Imagine – we had 100, 150 people in front of us, a generation who had been consuming weird music from Warp Records, through music from Mali – they know all that stuff is around them. And then when we started this club, and started playing 'Yah!' [included on Black Diamond] it was a complete surprise for everyone...." "Bringing Manu Chao and Warp together!" Kalaf grins.

"Almost no one could keep their T-shirts on," Barbosa enthuses. "Sweat was dripping off the walls. Really, really hot. We used an old PC laptop from Cash Converters, and it would shut down because of the moisture. That kind of dark and strange place."

On the second night, a month later, they realised something special was happening. "There were 200 people who couldn't get in. It wasn't marketing. Everyone was like: 'I just went to this night, and it's the Lisbon sound, finally.' Everybody had just spoken to each other."

Two years later, Kalaf shows photos from those nights on his laptop. The tiny stage where Buraka play swarms with tripping, gurning, twisting shapes. "We developed relationships from that night," Barbosa says. "The first dancers we worked with were cast then. We cooked the whole thing up on those four nights."

When the police closed that club, they moved to the Lisbon super-club, Luc's.

"That's when the formal idea of creating a band developed," Kalaf says. The dancers stayed, making Buraka Som Sistema an Afro-Brazilian-style spectacle. "We did all those summer festivals, and we brought a show. That attitude on-stage means that, even as a Portuguese-language project, we're not the underdog."

The impact of that tiny club spread from Lisbon to global interest in just two years. "The most important element was that we're DJs," says Barbosa. "People like Diplo and Switch played our songs and put them on mix CDs. That gave us visibility and credibility. But you need good songs to back it up, or people will give you 20 seconds of attention, then move on. Everyone we work with thinks the same way: fast, and now. There's YouTube, where I can just put a music video up and not worry about a single and the whole industry thing."

Buraka Som Sistema's first record was a Portugal-only EP of kuduro-sampling re-edits. Black Diamond is very different, it's limber grooves supplemented by sampled speeches on Angola's bloodily exploited diamond riches, and Kalaf's velvet spoken words. "Yes, we are rising. You are in London," he purrs on, "New Africas."
"But it feels like Rwanda, or Lisbon... here, communicate your feelings through the language of dance...."

"If you travel a lot, you get to see with your eyes," he says. "Africa, India, South America are influenced by satellite TV, computers, software, the same as the West. We study outside of my country, and we don't return the same. Africa's perceived like we're quite naive, like we're at starting time since the Europeans left. Of course, Africa's dust and confusion. But if you go to downtown Rwanda and you want to go to the airport, it's the same time as from downtown London to Gatwick. So if you have the same inner-city dramas and traffic jams, and more or less the same tensions, your mind understands. If you put an Angolan kid today in London, he will more or less manage."

"That's definitely one of the ideas we want to put out to people," says Barbosa. "We've been thinking of doing a documentary showing exactly this – and selling it to National Geographic, so they can show something else, other than elephants and lions...."

Buraka Som Sistema play The Twisted Pepper, Middle Abbey Street, Dublin, next Thursday