If you had gone down to Brixton Academy a week ago today, you might have had to pinch yourself to check you had not been transported to New Zealand. Despite being virtually unknown here, the headline act, Fat Freddy's Drop, had attracted a sellout crowd - most of them from their native land.
On the same night, on the other side of London, the South Bank became a little corner of Kurdistan for a concert by Aynur, at the Queen Elizabeth Hall. Over at Wembley Conference Centre the following night, there was a capacity crowd made up mainly of Indians for Bollywood's biggest musical superstar, Asha Bhosle.
What they all have in common is that they are almost completely off the radar of most music fans - even those with a taste for "world music". Yet they can (and do) sell out shows in London whenever they come here. And there are plenty more where they came from. Most of them are household names in their own countries; some are superstars. Yet their names are unfamiliar to most people outside their own expat communities in London.
"Some of these acts draw an entirely different crowd when they leave their home country," says Andy Wood, of the promoter Como No, which specialises in bringing Latin music to the UK. "Some Asian artists, such as the late Nusrat Fateh Ali Khan, would do two completely different gigs in London: art-house shows for a mixed audience at somewhere like the Barbican, and then a bigger venue for a mainly Pakistani audience."
Others, such as the Nigerian fuji star Barrister need never reach new audiences. "He can come and spend two months in Britain playing for exclusively Nigerian crowds," says Ian Anderson, editor of fRoots magazine.
And for every Baaba Maal or Youssou N'Dour who has found international success, there's another African superstar who remains unknown outside their home country, such as the Ethiopian singer Aster Aweke. "I once saw Aster Aweke in London, where I was one of only six white people in the entire audience," recalls Anderson. "Everyone else was from Ethiopia or Somalia."
While plenty of us enjoy music from all over the world, it seems we prefer it to sound "authentic" rather than a pale pastiche of what we know. The least likely acts to cross over are not the Tuvan throat singers, but those, like Aweke, who sing rock or pop, but in a foreign language. Juanes, from Medellin, in Colombia, is the biggest new name in Latin music, and sold out Shepherds Bush Empire last summer. But he has picked up few British fans because his style is what we would call soft rock and his socially conscious lyrics are Spanish.
There's a similar problem for Brazilian superstar Ivete Sangalo, who plays axé music. "In Brazil she's like a female Robbie Williams. We sold all our tickets the day they went on sale," says Patsy Lima, from Guanabara, a bar in London where Sangalo plays one of three dates later this month. "The audience here will be almost all Brazilian, because unless you can understand her lyrics, it just sounds like feelgood carnival music."
It's not hard to foresee a breakthrough for Fat Freddy's Drop, whose "hi-tek soul" - a blend of spaced-out dub reggae and dance beats, mixed with the sweet soul vocals of Dallas Tamaira - is at its best in their freewheeling live shows. But it won't be on the scale of New Zealand, where last year's debut album went gold on the day of release.
There was plenty of authentic flavour at the South Bank last weekend for Aynur and the Mikail Aslan Ensemble. Performers and audience were drawn almost entirely from the Kurdish diaspora - Turkey, Iran, Iraq and Syria.
The Bollywood superstar Asha Bhosle is not unknown here but, while we may associate her with Cornershop's chart-topping tribute "Brimful of Asha", we might struggle to name any of her songs. Last weekend's show at Wembley sold so well that another has been added this Sunday.
Greek superstar Eleftheria Arvanitaki is a household name in her native country; she's guaranteed to fill venues whenever she appears in London, but finds herself caught in the middle of two audiences. Her fame in Greece rests on what we might deride as Europop, but she went back to her roots for an acclaimed set of traditional Greek music at Womad.
Later this month, the Balkans will have its moment, with a double bill at the Islington Academy (25 June). Croatian singer Mojmir Novakovic combines traditional folk with dance music in his band Kries; and Kal, led by Romany brothers Dragan and Dushan Ristic, from Belgrade, are a far-from-traditional blend of Balkan roots, rock attitude, urban beats, Hawaiian guitars, tango, waltz and rap.
Some French performers are just too French to reach beyond francophones. Take M, the stage name of Matthieu Chedid. Half singer, half clown, he's as famed for his outrageous pink outfits and daft hairdo as for his theatrical music. Or Camille, an equally oddball singer who combines world music, jazz and avant-garde influences to often extraordinary effect. Both have sold out shows in London, but the audience was as French as a beret.
Italian pop seems strictly for Italians. Eros Ramazotti is as big a star as they've ever had but still relies on home support to fill a venue, probably because we tend to do this sort of thing quite well ourselves, thanks. The same goes for Zucchero, despite a couple of hit singles here (both duets) in the not-too-distant past.
The phenomenon of "huge at home, unknown in the UK" is not limited to foreign-speaking countries. Canada might seem like a country that's firmly integrated into the global pop landscape, but there are some musicians who remain its best kept secrets. Take the Tragically Hip, whose arena rock with an indie sensibility doesn't seem to translate. They rely on Canadians to fill UK shows.
There are plenty of Canadians, and Australians, when Xavier Rudd is in town. He's a surfer dude from Australia with a big following in Canada, where he is based. Perhaps it's the didgeridoo that keeps the rest of us away.
Dave Matthews was recently described as "the biggest rock star in America" by Rolling Stone. But on his rare forays to London the superstar performs in middle-sized venues to US expats.
Ivete Sangalo plays Shepherds Bush Empire, London W12, 21 June; Gunanbara, London WC2, 22 June; and Hammersmith Apollo, London W6, 23 JuneReuse content