Were you going to gigs when you were 14? Did you even really know what music was at 14? There are dozens of children in 93 Feet East tonight, and it’s disconcerting – we’re asked our age at the front desk, and the back of the venue is packed with parents.

This isn’t a question of ageism. It’s good that these kids are here, and perhaps there’s more than a smattering of jealousy that they’ve cottoned on so early. Bombay Bicycle Club’s members are only 16 years old and yet their technical proficiency and songwriting ability is masterful, their tunes twisting and turning through codas and choruses. It’s frightening, that’s what it is. Watching children nail something so perfectly. Making music that’s so fresh and of its time that you can only hope they’ve managed it subconsciously. Think too much about it, and talent like this will make you feel like a waste of space.

So perhaps it’s for the best that huge numbers of kids spend the gig wandering around aimlessly and flirting with each other, not listening to a damn note. Everywhere you turn there are mini soap operas being played out, spurned girls desperate for male attention and vice versa. This is a naïve, tribal crowd that jumps and claps and chats and squeals. They mean no harm; they’re wholly focused on the here and now; they do not understand the import of this music. Perhaps they’re in the right, embracing it hedonistically rather than wasting time trying to locate the Bombay Bicycle Club sound somewhere between the Strokes and Pavement.

However, there’s no escaping the annoyance of the stage invasion during the final song of the night, ‘The Hill’. Suddenly the band look old in comparison to their fans as the feral youngsters pile onto the stage, flailing their camera phones about, and bashing into their erstwhile heroes until the song grinds to a halt. “We’re not 14, and we want to hear the rest of the song,” some beardy bloke at the back shouts. Tough luck, mate. That’s your lot. The show has just petered out. Still, it was flabbergasting while it lasted.

As an aside to all this, there’s a dodgy character meandering his way through the crowd tonight, a middle-aged man dressed as John Lennon; a broad shouldered, six-footer with a screw loose. He lurches his way around, tripping over limbs. To begin with, he seems harmless enough. But after a while a pattern emerges. He’s looking for something. He stops repeatedly, making eye contact with young girls and trying to engage them in conversation. And then, if not immediately rebuffed, he briefly crosses the line, leaning forward to kiss them on the cheek.

It’s deeply troubling, and it raises an important question about security at gigs. Fair enough, have an all-ages show and ban the kids from drinking. But isn’t it a tad naïve of the organisers to think that alcohol’s the only risk to these kids on a Thursday night in Shoreditch?