Much of the attention at Touch and Go’s 25th anniversary celebration this fall went to bands that were reuniting, but I was more excited about the Ex, who’ve worked constantly for 27 years without ever growing soft or complacent. Never afraid to venture outside the postpunk comfort zone, the Amsterdam-based combo recently composed music for a Dutch stage production of A Clockwork Orange (in which they also played antihero Alex’s droogs) and collaborated with 71-year-old Ethiopian saxophonist Getatchew Mekuria on the just released Moa Anbessa (Terp). Mekuria’s mile-wide vibrato and gorgeously burred tone have earned comparisons to free-jazz icon Albert Ayler, and the band complements his ferocity with rumbling guitars and elemental drumbeats that push the tunes light years beyond typical world-music schlock. But tonight’s set will consist of straight-up Ex music. After the departure of bassist Rozemarie Heggen last year the group decided to become a quartet, with Terrie Hessels and Andy Moor switching over to baritone guitars to fill up the low end with percussionist Katherina Bornefeld. The change has renewed the bracing physicality of their songs: with vocalist G.W. Sok barking sternly in front, they sound like an ultra-amplified drum brigade. DJ Rupture and Comorevi-Butter Fly open. a 10 PM, Empty Bottle, 1035 N. Western, 773-276-3600 or 866-468-3401, $12.