One of the certainties of life in Addis Ababa is that the rainy season will knock out the phone network. Tsedenia Gebremarkos-Woldesilassie, one of Ethiopia’s most celebrated and decorated singers, is driving through the city at high speed, yelling into her mobile, intermittently apologising as the line fractures and drops, recalling the encounter that will soon bring her to England.

“A guy I knew called Dan contacted me and said there’s a guy who wants some music. We recorded some in the backyard, just a bedroom thing. His friend Nick came to meet us and said, ‘Will you be willing to work with me?’ I just said: ‘Yeah, sure.’ I didn’t take it seriously.”

The Nick in question was Nick Page, the English musician and producer who goes by the name Dubulah. He worked the contributions from Gebremarkos-Woldesilassie and her friends into a sparkling concoction of blazing Sun Ra-styled horns, Ethiopian jazz and deep echoing dub and called the whole thing Dub Colossus. Last year’s album A Town Called Addis won them critical acclaim, awards and an appearance at Glastonbury. Now they are returning to the UK for a concert at Dingwall’s in London this Wednesday and at the Womad festival later this month.

Page has a long history of this kind of collaboration. He was the only white boy in his school reggae band in London’s Hackney. He worked his way through a series of reggae bands, from The Bees to the Reggae Philharmonic Orchestra. For years he lived in squats with “seven carrier bags and one guitar”. The nadir was stealing sand from a children’s playground to make cement to keep a wall intact. “I never got over the guilt of that,” he says.

Things looked up when he became one of the founders of TransGlobal Underground, which pioneered cultural fusion between the different musics of the world in the 1990s. “We were the true Britpop, not sentimental retro crap. This [he waves around the St Pancras neighbourhood where he lives] is what Britain really sounds like: a mixture of everything.”

The initial agreement, as Page recalls it, is that the band would release one single and never play live. “So you can see how that turned out. We went from being in a Transit van to being in a tour bus. You earn more money, you spend more money, you end up in the same place.” Page spent six years with TGU, “five of which were brilliant,” he says diplomatically. A conflict over future direction meant that he eventually left, along with Neil Sparkes, to form the harder-edged Temple Of Sound.

Dub Colossus was born from a chance discovery in Sterns Records, London’s world music mecca. Here, Page came across the Éthiopiques series of CDs, curated by the French producer Francis Falceto, which anthologises the 1970s golden age of Swinging Addis.

Page became fascinated by Ethiopian music. The recordings he was listening to were made in the dying days of Haile Selassie’s empire: American R&B refracted through an Amharic prism, with unearthly pentatonic scales.

When Selassie was toppled by the Derg, all this came to an end. “When the Stalinist military regime came in,” says Francis Falceto, “almost overnight, the vinyl stopped, the big bands closed.” Live music died. “There were 18 years of curfew.” Gebremarkos-Woldesilassie remembers, as a four-year-old, seeing the bodies the Derg would leave in the street as a warning to the populace.

More for amusement than anything, Page made a dub mix of some samples, notably of saxophonist Gétachèw Mèkurya. (Falceto promptly claimed half the publishing rights for Mèkurya.) As his interest grew, he started to look for contemporary Ethiopian voices. The musician Dan Harper, then working in Addis Ababa for VSO, the development organisation, rounded up friends and contacts, including Gebremarkos-Woldesilassie, the saxophonist Feleke Hailu Woldemariam and the singer and club owner Sintayehu “Mimi” Zenebe.

In August 2006, Page travelled to Addis Ababa to record. “I had no intentions of making an album, but this had all the things I love most. My favourite reggae band were The Abyssinians. It’s all part of the same journey: music travelled from Africa to Jamaica to London. And of course 1970s Addis was full of grooves and funky dance. Alèmayèhu Eshèté was James Brown; Mahmoud Ahmed was Elvis ... Everyone relates Rasta to Ethiopia, but a lot of Ethiopians don’t like Rastas at all. They’re churchgoing people, very strict.” Page, who was thrown out of the Greek Orthodox church as a child (“my sister and I used to piss about”), took satisfaction from mixing an early draft of the album in Athens, where the 1970s records had been pressed.

Page also fell in love with the Ethiopian capital, having used Arsenal Football Club as a way of bonding with the immigration officials. “I’d advise anyone to go to Addis; it’s one of the safest cities in the world,” he says. (His benchmark, it should be said, was set by six weeks producing the punk band Los De Abajo in Mexico City.) But the damage done to culture in the 1980s was still evident. “Some Azmari musicians were killed for criticising the Derg. They’re still recovering from what went on.”

Page and the Ethiopians recorded under a corrugated iron roof in a studio made of breezeblocks, the sounds of the city drifting in from outside. He returned with the kernel of an album’s worth of songs. When Falceto’s plans to release the record fell through, Page turned to Real World, the label set up by Peter Gabriel, and brought the Ethiopians to the label’s studios in Wiltshire for further recording. “I liked the paradox that we started with urban field recordings and ended up with high-tech pastoral,” he says. The Ethiopians were unfazed by Gabriel’s bleeding-edge studio technology, but Mimi was overawed by the size of her bath, a swimming pool for the diminutive singer. The Wiltshire sessions reworked about half of the existing album.

For Page, “Dub Colossus is all about live.” The live debut of the project could not have come on a larger stage: “Glastonbury was a baptism of fire.” Gebremarkos-Woldesilassie says: “We weren’t used to that kind of audience, the younger, hippy generation. I can say they never heard anything like that before.”

Oddly, Dub Colossus may find its home market the hardest to crack. “Ethiopia is a closed society,” says Gebremarkos-Woldesilassie. “We do stuff in our own way. We don’t promote ourselves outside like the west Africans.” In some ways, it is backward-looking. “Elsewhere in east Africa it’s all hip-hop and ragga; we do appreciate modern music but mostly traditional styles.”

Gebremarkos-Woldesilassie hosts a radio show, Love Songs, on Addis’s private radio station, Sheger FM. But Dub Colossus has yet to find favour with her audience. “It’s a bit heavy for them. They say, ‘It’s quite ...’ ” – her voice mimicking their disapproval – ‘interesting ... ’ ”

Dub Colossus play at Dingwall’s, London, on July 8, at the Womad Festival and at European festivals. An EP, ‘Return To Addis’, is released by Real World