Photograph by Steve Asenjo

It‘s an uncomfortable undertaking, going to see a band with whom you had a teenage love affair. The risks involved are numerous and troubling. For a start, it’s not unlikely – if your taste was as poor as mine – that moments into your reminiscence, the slow and gut-wrenching fear that your enamour may have been misplaced may be realised: it might just turn out to be a little bit shitter than you remember. Sorry teenage self.

In getting a little older (and a little fatter) it’s also entirely possible that they’ll have lost whatever emotive spark it was that the slimmer you so adored, regardless of how your tastes have changed. Even if the band are essentially still the same, it’s always going to look a little sad if they haven’t moved on at all.

It’s with a mood of cautious anticipation, then, that we enter this dangerous territory tonight, for Canada’s angsty twins, Tegan and Sara, in North’s London’s HMV Forum. Identical at birth, both lesbian, and both the objects of my teenage adoration during their earlier days, the pair epitomise this feeling of unease. Live, for me, Tegan and Sara are a fairly high risk investment.

A few songs in, however, and ‘Back In Your Head’ relieves the tension a little. An instant and visceral link back to younger days, the childlike keys and familiar vocals leave eyes gleaming down on the stage from the balcony, where those with a few more years to look back on huddle together in group nostalgia. Below, meanwhile, the fresher of the audience members emote first time round to the undeniably teenage themes of ‘The Con’ and ‘Nineteen’. Whatever your position, though, there’s a slight feeling of relief: From here, things can only go up.

It’s something of a shame, though, that ‘Nineteen’s low-in-the-mix vocals and and surprisingly clean guitars don’t make quite as much of an impact as we might have hoped. It’s reflected in the noticeably lacklustre reception from the audience, too: no dancing to be seen here. Things are brought back to a satisfying climax, however, as the room sings along with heart-felt affection to ‘Alligator’, before ‘Living Room’ brings a Mumford-esque folky tone to the proceedings.

Simple synth melodies, avant-pop percussion and heavy pop-punk guitars largely back up the slightly grating, almost hyperbolic Calgary-Canadian accented vocals for this earlier material, but there’s a marked change here in the more recent tracks – and not necessarily in the way you might imagine. The band’s sound has morphed, for sure, but evolving into something more adult, subtler, is not what characterises the movement. New single ‘Closer’ bears all the hallmarks of classic Tegan and Sara lyrical love-lorn lamentation, but gone are the distorted guitars and faux-grunge sensibility. The track is an unashamedly synth pop spectacle .

Largely, though, taking the risk pays off. No teenage memories are ruined, and it’s essentially an entertaining set, full of charisma – even if the explicitly detailed stories of the twin’s birth weight seem a little out of place. The best show you’ll see this year, this isn’t, but as an enjoyable sojourn into pop-punk nostalgia and emo sensibility, it’s far from a bad night out.