Lauren Bravo writes: She’s one of fashion’s favourite mythical figures, along with the woman who actually has a capsule wardrobe and Mariah Carey’s ‘stylist’. She reappears in some shape or form every season, manifested in leather jackets, slashed t-shirts and smudgy eyeliner. She’s a household name, bandied around in fashion houses and ladies’ loos alike.

But she rarely delivers everything she promises (supposedly because she’s hanging out backstage with Iron Maiden; really because she’s made up by magazine editors with no imagination). She’s the ‘rock chick’: three parts reputation to one part nifty alliteration.

The tricky thing about rock chick as a trend is that, like many other mythical beings, as soon as you lay claim to it, it doesn’t exist anymore. Nobody who is actually a rock chick would ever use the term ‘rock chick’. It’s a linguistical rip in the space/time/style continuum. Just as nobody who calls themselves ‘kooky’ ever really is (see also: quirky’, and ‘I just rolled out of bed and threw this on’), any girl who sums up her style as ‘rock chick’ generally hasn’t been any nearer a moshpit than Medium level on Guitar Hero III.

So what maketh the rock chick? If we’re following the fashion definition, there are some basic ingredients:

Leather. In jacket form if you’re a novice; in trouser form if you’re a divorcee who’s just finished at Slimmer’s World.

Studs and chains. This season especially, studs and chains are embellishment of choice. Think of it as the pain-free alternative to facial piercing.

Band t-shirts. Here I feel duty-bound to repeat the old adage – if you can’t sing at least three songs by the band, you CANNOT WEAR THE T-SHIRT.

Eyeliner. In fash mag speak, this should look like ‘last night’s make-up’ (ie. be crumbling down your face, and giving you those little black globules of sleep in the corners. Nice). Because rock chicks are too busy doing debauched things on tour buses to use a cleansing wipe.

Ripped tights. A man once chased me all the way up Tottenham Court Road, just to tell me I had a ladder in my tights. He didn’t get the grateful response he seemed to expect – instead, I snapped back, “Yeah, SO? I am AWARE. What do you want me to DO, run home and change? It’s a LADDER, it’s not like my BOOB is hanging out.” I realise in hindsight that my reaction was wrong. I should have calmly told him I was ‘channelling rock chick’.

So I’ve come to believe that fashion’s obsession with the rock chick is a question of good PR on behalf of the whole industry. Because fashion types tend to be regarded as uptight, controlling, slaves to perfection (does Anna Wintour’s hair ever move? Have you seen it?); and rock chick is the antidote to that.

The rock chick stays out all night, drinks beer, not champagne, dances until she’s sweaty and eats a kebab on the way home. So as a form of damage limitation on their image, fashion people have commandeered her and repackaged her as their own creation. She is ‘dishevelled’ (messy), she is ‘nonchalant’ (doesn’t give a rat’s bottom) and she is ‘full of attitude’ (might throw an amp at your head).

And it’s easy to keep on believing in the rock chick, because there are plenty of celebrity purveyors of the myth. Kate Moss is the classic – she dates indie musicians! She goes to Glastonbury! She’s always got a fag on! But Kate’s cover is blown each time she opens her mouth, and instead of the whiskey-soaked growl of a true rocker, out comes the squeaky bleat of a Croydon schoolgirl.

Then there’s Amy Winehouse, who was perhaps one of the most authentic poster girls they had, until her rockabilly aesthetic passed out of fashion favour and her St Lucia rehab stint made her hair go crap. The most successful pretender to the throne currently seems to be Taylor Momsen – the precocious little upstart who has earned her place in rock chick mythology by playing Jenny, the ‘edgy one’ on Gossip Girl.

Overlooking the fact that calling someone a rock chick for being the ‘edgy one’ on Gossip Girl is like giving someone a Nobel Prize for being the ‘clever one’ on Big Brother, Momsen’s look is a checklist of rock chick accoutrements. Ripped tights, week-old eyeliner, tangled nest of peroxide extensions. She is also, however, the face of New Look S/S 2010 – a nice move on the store’s part, but for Taylor it’s about a 1.5 on the scale of credible rock and roll moves, just above Iggy Pop on the insurance billboards and John Lydon advertising that butter.

So you can’t help but wonder, is Ms Momsen just another in the long line of fashion-created ‘rock chicks’ that we’re meant to follow blithely with our kohl pencils and ‘I’m with the band’ t-shirts, until she gets bored and Rachel Zoe attacks her? Just remember this, ladies – every time you say you don’t believe in rock chicks, a rock chick somewhere DIES. Whether that’s a good thing or not, I’ll leave you to decide.