It's a single that follows all the formulas for a successful emo sound, but still manages to suprise you every time the pleasingly fuzzy guitars kick in. Biffy Clyro are a three piece with an energetic, dark emotional sound. Quiet, simple but intense guitars, slightly tortured sounding vocals and bursts of minor-key noise. You know the score... or do you? They leave me undecided. They have a more pleasing hardcore sound than tamer emotional indie contemporaries. During quieter moments post-rock tinges creep into their sound too - the inexplicably named but equally good b-side "Instructio4" adds a violin to sinister guitar riffs and dreamy vocals. And when it goes loud, that sad intensity of it puts any nu-metal attempt at anger to shame. Infact I prefer this to A-side "27", which is quite catchy but relies more heavily on the quiet-LOUD grungy sound which we all know just a little too well. This is no bad sign as the track would make an obvious single choice - along with the other tracks it gives us a good idea of their potential. We finish with "Breatheher", a straightforward but beautiful acoustic track with harmonies and a whistful folky sound. Biffy Clyro seem a well-rounded band and based on this I will be looking forward to any future album.