I was pleased to figure out that Ennio Morricone wrote this song. I liked it either!I found this sound from the Django Unchained soundtrack and even though I have no idea what the song is about, I still love it. It's in Italian.
This effect (hypnotic like) is due to singing on relaxed vocal cords. Therefore, it's associated with whisper (actually, it IS whisper with the admixture of odd overtones, which are percepted as musical sounds by human ear).🗣〰I don't know what it is about this guys voice, but their songs are almost hypnotic like.