"This is a song to dance to while thinking about your mother," says Jehn, sullen French vowel sounds dragging their heels on their way out the speakers. In other, lesser frontpeoples’ mouths it’d be a gag-worthy declaration, but in the context of a commendably louche set this evening, the dancing could well be a euphemism.

Because, loathe as we are to say it about a boy/girl duo of Gallic origin, John & Jehn are a bit... seedy. But not unromantic. Like The Doors doing minimalist chanson, or secret blossoms sprouting between pavement cracks of the semen-smelling alleyways of Montmartre or Soho. They’re basically great and should be coming up roses by the time their debut album hits in February.

Elle S’Appelle’s vaguely-post-punk indebted pop bounds around with all the enthusiasm of Andrex puppies for the first ten minutes or so of their performance this evening, after which frivolity you realise they’re bringing you out in an appalling rash. Their good-natured exuberance is lent a degree of individuality by Lucy’s gravelly organ tones, and brings to mind the breezy excellence of Sky Larkin, but equally there’s a lack of guile apparent in their songwriting, an unfortunate schoolyard whiff which suggests they should stick to the elastic ties ‘til they’ve learned to master the Windsor knot.

On to the main event. Picture the thought of four-foot tall, bob-cutted vamps with puckered doll features coming in their droves through doors left ajar and carrying you off in your sleep to an unmarked grave. Brilliant: now you’re most of the way to imagining Ipso Facto if they succeed in attracting a sizeable fanbase.

‘Harmonise’ sounds great with its ringing, chilly hooks and ‘Balderdash’ is a fine rockabilly rollick, but it’s the new material which showcases a willingness to experiment, particularly in the rhythmic stakes, that promises much.

They’re a band on the devil’s payroll, and not just because they’re heading up an Artrocker bill; a freak-show burlesque of pop noir to send a nation’s ambulance force careening down cul-de-sacs while people die screaming in terrific-sounding agony. ‘Eyes Of The Blind’ sounds like in-denial vampires applying lipstick in the mirror, while ‘Smoke & Mirrors’’ clever, awry rhythms resemble the theme tune to When Playgrounds Go Bad, kids being flung from overheating roundabouts in slow motion.

Ipso Facto, then: doing the devil’s work, hands anything but idle.