"It's great to see you in this super-cool venue," says Gabriela Quintero, one half of the Mexican semi-acoustic duo, Rodrigo Y Gabriela, admiring the whooping crowd standing between the wrought-iron columns of this 19th-century steam engine repair shed.
The Roundhouse in Chalk Farm shows off the Latin spirit so well. This is where the Argentinian dancers of De La Guarda and Fuerzabruta took London by storm a few years back with iridescent displays of acrobatics set to tribal rhythms. All the fervour of those shows is to be reignited tonight, improbably perhaps, by a pair of acoustic guitarists poised on stools.
Quintero punches out the rhythms of tracks such as "Juan Loco" and "Satori" with her percussive open-handed flamenco playing. Rodrigo Sanchez enlists the audience as an auxiliary rhythm section, syncopating one half of the clapping crowd against the other.
The couple have to pack in the sonic fireworks tonight, as this is their only UK gig this year. They first played together in the thrash metal group Tierra Acida in Mexico City, but abandoned that to go busking around Europe, where they developed their more classical style. The lean years are now behind them: their second studio album, Rodrigo Y Gabriela, has gone platinum in Ireland, their country of residence. It has sold more than 100,000 copies in the UK and half a million worldwide.
The tracks from that album form the cornerstone of their live act, including covers of Metallica's "Orion" and Led Zeppelin's "Stairway to Heaven". A sing-along of Pink Floyd's "Wish You Were Here" is now also firmly embedded in the set.
But it is the material that they toured throughout Britain last year that draws the loudest cheers: the melody to "Vikingman" is sung out like a football chant by the crowd who have been honed into a clapping machine as tight as a pair of maracas by the time the couple launch into album-opener "Tamacun".
They return for an encore with the rollercoaster ride of "Diablo Rojo", named after a theme park ride, and leave the adrenalin-pumped audience with the tantalising promise of a new album "sometime next year".