Interesting article, from a foreign view. In the rural zones the tradition still is hot, not as the old days, because the modern era is implacable, but in some places you could find that people. Sadly, in all south american the coups were interfered and orchestrated by the yankees pigs, specially the CIA, instilling their capitalist to abolish the origin people traditions, ruin the local economy and corrupt the political system.
Anyway, you couldn't find some interesting labels/projects (from a "evil" or "sick" view) here, because the scene is very young and most are focused on social themes or simply in whatever (like the projects in that comp). Maybe I could recommend "Total death propaganda" from Chile. Is not 100% focused on noise, but their energy is really sick. Vintras was a good industrial project, like GO and a swedish touch... And of course my label OMM hehe. Maybe there exist others in the utter underground, but at least not in Chile.
To the southamerican old and new metal scene, there aren't words; you can find a neverending list of sick bands.
