>>28781To me only loather sounds black metal, although I am pretty sure that it is an actual black metal song with a drum track over it. Held out notes, pads and drones are pretty common in electronic music. I doubt there's a direct influence between the two scenes. They sound similar because that's how "dark", "evil" and "oppressing" atmospheres sound like, regardless of genre. Maybe it comes from horror movie soundtracks or even classical music, I have no idea.
But this is only my bedroom analysis, maybe I am completely wrong.