Pure, honest and unabridged music and art - a definite rarity. Death metal is free jazz. Far and away the best band to come out of Chicago since Veruca Salt. Their semen is made from hellfire, and to have it in you is your greatest desire. The only group on the planet that can be forgiven for directly influencing thousands of godawful hiphop, house and electro-pop bands.
Some members are also accomplished artists in other mediums.
The original power-electronics act, still taken way too seriously by fans and critics alike. Of special note is the Sound Transmission Project. The European Free Improvisation Pages - an excellent resource. The site this here links page is connected to, just in case you missed it. TX record store and home of the Fleece and Loveletter labels.