The infectious rhythms of Dengue Fever

The day after a sweaty debut appearance at the Borderline in London, assorted members of Dengue Fever are grouped around a table in the bar of the Columbia Hotel in Lancaster Gate. Plans are afoot: food for some, for others, music. Senon Williams, the bassist whose home studio is where much of their new album, Venus on Earth, was recorded, is still in the twilit world of jet lag, grazing on Kronenbourg in the shabbily grand confines of London's premier rock'n'roll hotel.

For many US bands, the Columbia is akin to Rick's Café in Casablanca. Since the Seventies, virtually everyone in rock'n'roll has passed through. "It's kind of stinky and damp, and the lights flicker, and there must be ghosts in the rooms because they keep creaking," says Williams, "but we love it here. I could stay here every time I come to London."

The uninitiated might be forgiven for thinking that Dengue Fever is the result of some feverish hallucination in a tropical emergency. But they're the real thing, an inspired combination of soaring Cambodian vocals from lead singer Chhom Nimol, and West Coast psychedelia as seen through the colour-drenched lens of Cambodia in the swinging Sixties.

Picked up here by Peter Gabriel's Real World label, Dengue Fever's latest album, Venus on Earth, is their first UK release, much of it recorded on analogue tape using the same generation of decks that The Beach Boys used in the Sixties at Oceanways Studios. These are songs that cross multiple time zones, with sonic textures ranging freely from psychedelia to surf, mariachi to garage rock, and even Berber rhythms and Ethiopique sax. And as well as the record deal with Real World, they'll be performing at this year's Womad, whose organisers describe them as nothing less than "the grooviest band you don't yet know".

"We're really delighted to have them perform at Womad this year," says festival programmer Nicola Henderson. "They are going to be the must-see band for this summer."

The Dengue Fever story begins with Ethan Holtzman, the man behind the humid, floating sound of the Farfisa organ. After visiting Cambodia in 1997, he returned to LA loaded with vintage Sixties Cambodian pop, a hitherto unknown genre of world music, steeped in the sounds pumped out by the American Forces that were then in Vietnam. A classic case of musical blowback.

Holtzman's brother Zac had become similarly enamoured of Cambodian pop, stockpiling tapes in the Echo Park apartment they shared. It helped that they had Cambodia Town on their doorstep in Long Beach, the West's largest concentration of Khmer-speaking folk. It was there that they tracked down Nimol, one of Cambodia's biggest singing stars, and persuaded her to join forces with this curious band of indie musicians.

Joining them for the ride was David Ralicke, whose damp, rusty sax lines fill out the songs with strong riffs and humid tones; and drummer Paul Smith, who doubles up as sound engineer and producer. Bassist Williams provided the studio, and having visited Cambodia himself in 1995, he had his own stack of tapes with garish covers of singers in Beatles-esque suits and Austin Powers hair, and women in psychedelic dresses and towering beehives.

The few clips of film that survived the murderous ascendance of the Khmer Rouge are poignant, a haunted party music from a time and place that no longer exists. So much was destroyed, of course, and millions killed. Nimol's family escaped to Thailand. Others fled to Paris and the US, and brought the music with them. Decades later, the diaspora had coalesced into the Cambodia Town of Long Beach, where the band went in search of a singer.

"We went to this club where they'd have bands with six or seven rotating singers, and there'd be an artists' table full of food and drinks – Nimol still plays those clubs. Weddings, birthdays, New Years," says Williams. They tried out others before chancing on Nimol: "We had no idea she was from this famous, Michael Jackson-type musical family. The other singers thought we were nuts, saying, 'No way is she gonna come'. I think she was just intrigued by what we were doing."

Their first show was at a tiny indie club in LA, and the response was immediate. "The crowd went nuts. LA isn't a dancing town, especially in the indie scene, but these hipsters were rolling around on stage. It was like a crazy dance party. It got everybody jazzed."

Their album debut in 2003 consisted entirely of Cambodian pop songs from the Sixties. Nimol's vocal ornamentations and improvisations – one of her specialities is the "ghost note", jumping from one scale to another – are embedded like a sixth sense in the band's trippy mix of American psychedelia and surf rock, spinning the music up into the stratosphere.

"Our concept was not to be a Sixties cover band, but to be influenced by the music and to create a band out of it," says Williams. But at the beginning, with Nimol barely able to speak English, and the Americans no better with Khmer, the attempts to record original material ground to a halt.

"We couldn't get enough even to do a set, so we decided to be a covers band on that first album. Nimol brought in songs, and we'd scour the stalls on Long Beach for tunes we liked."

For their second album, 2005's Escape from Dragon House (the name of a Long Beach nightclub where Nimol still performs), Zac Holtzman started bringing in the vocal melodies for the band to work on, while Nimol was often holed up at their Echo Park apartment, turning English lyrics into Cambodian songs. She now she mixes the two languages with ease. Check out the wonderful "Tiger Phone Card" from the new album, a duet of Zac's frail American vocal and Nimol's impassioned and beautiful phrasing, it tells the story of a transcontinental, cross-cultural love affair.

Escape from Dragon House was recorded after a month-long tour of Cambodia – Dengue Fever are the first American band ever to perform in the country. The impact on everyone involved was powerful – even overwhelming – and was captured on film by the cinematographer-turned-director John Pirozzi with a local crew. Due for DVD release in the autumn, Sleepwalking Through the Mekong tells the story of Nimol and the band, and more important, opens the doors on the music and stars of a lost generation of Cambodian music that found its feet – and its soul – in American pop to produce a truly unique, long-lost hybrid.

The day after their arrival, they were filmed for Cambodia's national TV station CTN, a two-hour special mixing interviews with songs. It ended up being broadcast three times every day for the whole month they were there. "I'd never experienced recognition or fame," says Williams, laughing, "until I got to Cambodia."

Nimol's mother and relatives were at the recording session. "They knew she was coming back but she didn't tell them we were playing Cambodian music. They were expecting her to sing Madonna, not pre-Khmer Rouge Cambodian psychedelia. They were blown away with our performance."

They played free gigs across the country, from mountaintop temples using battery-powered amps, to the riverside slums of the Ton La Basae district in Phnom Phen, the improvised stage lighting made up of the tail lights of cars powered on a noisy, churning generator and a higgledy-piggledy tower of randomly assembled speakers on one side of the stage.

"It was one of the most epic shows I've ever played," says Williams. "I had culture shock at first. It was totally wild, the poorest place I'd ever seen. Heaps of trash, people with bandages, very sick-looking, just hanging out. The crowd was completely still, completely silent, didn't even clap between songs. Crazy faces with crazy expressions."

Given that Dengue Fever are embarking on their first tour of UK open-air festivals – the likes of Glastonbury, Womad, Lovebox and Larmer Tree – a sea of crazy faces with crazy expressions could be the order of the day if the summer conspires to be another washout. For festivalgoers, meanwhile, prolonged exposure to Dengue Fever is likely to bring on delirium and involuntary movements of the legs and arms. You have been warned.

'Venus on Earth' is out now on Real World; Dengue Fever play Womad (http://womad.org), 25-27 July