There are two problems with the “math-rock” musical sub-genre. Firstly, the term itself suggests a stuffy professor blankly reading algorithms, rather than creative sonic expression. Secondly, too often the bands involved sound just as businesslike, with their complicated rhythms and stop-start dynamics satisfying the mind but not the heart.

Case in point, main support Canterbury’s Delta Sleep were a decent warm-up and obviously skilled musicians. Blending that patented Battles twiddly guitar sound with the standard post-rock build-up to crashing crescendo, they did everything right, though somehow came up lacking – a charge impossible to level at the headliners.

It’s been a tough few months for Belfast mostly-instrumental four-piece And So I Watch You From Afar. Having lost founding member guitarist Tony Wright, it must have been hard work teaching a newcomer their complicated style, though it clearly paid off. From their name, you’d be forgiven for expecting sappy post-rock clichés of glacial guitar drizzling, though this gargantuan display crushed that thought immediately.

With loud-as-hell guitar blasts wrangled into something resembling underground dance (almost dubstep-sounding at times), alongside metal volume and hardcore punk energy, And So I Watch You From Afar’s angular, pulsating set glowed both literally (pretty lighting set the scene) and metaphorically. The odd lull (single Seven Billion People All Alive At Once, insipid by comparison) and a blown amp simply couldn’t stop this crowd-surfing (and crowd-cowing, as guitarist Rory Friers ordered the moshpit to its knees) spectacle. This uncompromised, intelligent rock left ears ringing and a packed Audio nicely shaken up.