As you probably aren't a 16-year-old girl whose pastimes include screaming at the top of their lungs, chances are you are unfamiliar with The Janoskians.
Five young, alarmingly tattooed Australians, they started out as tacky online pranksters (think Jackass minus the wit and grace), an inauspicious origin they have parlayed into what, from the back of a heaving theatre, looks suspiciously like an actual pop career.
Before a hyperventilating Olympia the quintet - a blur of cheekbones, cheeky chap grins and gravity defying hair - came across as a sort of cut-price One Direction: charismatic, after a fashion, but raw and silly with it (you imagine Simon Cowell telling them they are a work in progress and to come back next year).
They sang, they rhymed, they dispensed vast quantities of banter - all greeted with yells that soared so high you were glad the guy at the door had quietly slipped you ear-plugs. It was impressive in its way - and quite terrifying also.
Musically, The Janoskians are obviously somewhere to the left of inconsequential. Their repertoire felt like a facsimile of a facsimile: there was rapping, the occasional lurch towards a chorus. As is the fashion among boybands nowadays, early 2000s bubble-gum punk was the audible influence.
Though most in attendance were surely too young to realise it, at moments the evening felt like a tribute to the pioneering spirit of Busted and McFly, the outfits to which The Janoskians are most clearly in hock (two of the five carried guitars, which they occasionally appeared to strum).
Not that the spirited-yet-limited repertoire was of any consequence. The Janoskians have all the ingredients a smash boy-band requires: dizzying quiffs, a facility for bubbly chatter; falsettos that somehow made themselves heard over 1,300 squealing teenagers. What they lack is a potential break-out single - all of their material seems to run together, a great, soggy mess of perky melodies and lyrics.
In the short term, this will not detain them in the slightest. They've sold out multiple nights at The Olympia; their YouTube videos draw millions of views. Even without a genuine hit or TV franchise, they're doing perfectly well (and far better than they ever dared dream).
In the longer run, however, they are probably going to have to decide which they wish to be: internet novelties or a proper band with a proper career path. If it's the latter they will have to hook up with songwriters and somehow get their mugs on television. Otherwise, filling mid-size theatres may turn out to be the outer limits of their achievements.