The accordion, it’s fair to say, isn’t the coolest instrument in the catalogue. Tainted with the faint whiff of leering clowns and forever tied in the mind to that most torpid of all musical backwaters, Morris dancing, it’s rare to see the old squeezebox grace the stage of a trendy London venue. And that’s a shame. Because when played well, as this fantastic gig at Charlotte Street Blues showed, the humble accordion can form the centre of one of the most electrifying live spectacles around.

Dwayne Dopsie can play the accordion. And I mean really play it. Strolling on to the stage after two lively introductory numbers from the Hellraisers, he quietly steadied himself over his intricate instrument. After two minutes, his huge muscle-bound arms were slamming back and forth and his fingers whirlwinding over the innumerable keys. After five, sweat began to drip from his constantly dipping and weaving brow. By 15 minutes in, it was being flung up in long arcs, threatening to soak anyone less than six feet from the stage. The sheer passion and energy was fantastic.

Energy is the name of the game for the Hellraisers. While Dopsie juddered and contorted over his accordion, his young bandmate whipped around the stage to his right on his frottoir. Another instrument you don’t see enough of, that. The frottoir is a chain-mail-like adapted-washboard worn over the chest and scraped and bashed with two spoon handles. The range of the instrument was showcased with a series of astoundingly athletic solos.

Over two sessions, split by a short break, the band cranked out epic, frenetic blues-infused zydeco numbers that sent the audience zinging around the dance floor. Where’d my Baby Go?, number one in the Bahamas for three months, and a cover of Hendrix’s Hey Joe went down particularly well - and the crowd built slowly to a bobbing throng as the evening progressed.

Periodically, from the back of the stage, the Hellraisers’ guitarist, who resembles a slightly-less-grizzled Carlos Santana, slinked forward to peal off a gorgeous solo, all the while maintaining a flawlessly stoic stare. In almost any other band, he’d be the one to draw jealous gasps.

But this time, for once, it was the sweaty guys toting accordions and spoon handles who really looked cool.