Thank you for responding - I was beginning to think no one found my post interesting. I could have stolen some images from the web that I think folks would find quite interesting but as a quasi-photograher I won't allow myself to use images that aren't mine or at least in the public domain. Go here for some - https://www.instagram.com/amplifiedhistory/
The videos of their concerts are quite compelling I find. Great rhythms for a weight room work out also.
Heilung's "music" is very powerful, with heavy drum beats, and a very throaty rhtymic chanting like a Native American war dance or something - or a pagan ritual bordering on sacrifice. It is not heavy metal as much as neolithic chanting or sorcerism, or a band of brothers preparing for battle.
After listening for a while I decided the throat singing almost sounds like someone who has had laryngectomy, or maybe a tracheotomy, and uses a microphone to amplify the voice. The fact that they wear masks to cover their faces may increase the effect as well.
The northern Europeans, the forefathers of the Vikings, and the Visigoths, were quite feared in their day, and these performances seem to hark back to those days - or maybe I am just imagining all this. A stage filled with half naked warriors with stone tipped spears and round leather shields must have some purpose to the performance.
I would love to hear what other people think of their performances.