The dynamic second album from Killing Joke set the standard by which their career is judged as a whole. Jaz Coleman is maybe off his rocker in real life, but on record he's a focussed machine gun. Tribal drumming from the legendary Paul Ferguson is the heartbeat. Throw in Youth's bass lines and Geordie Walker's echoing guitars and you have a classic that inspired everyone and everything that followed in the industrial genre. I'm not exaggerating its importance. Listen to Ministry's The Mind is a Terrible Thing to Taste (1989) after hearing What's THIS For...! and you'll wonder why Jaz didn't call his lawyer.