I grew up with the slogan "kill your idols", but whether I wanted that or not, I became a 100% fan of Diamanda Galas.
Her voice, with a range of 4 (!) octaves, has no comparison in this world, and that exactly is what your chilling spine will tell you when listening to her.
She once said "My voice is an inspiration to my friends and an instrument of torture to my enemies", and this was no bragging at all.
I saw her perform Defixiones live in an old castle in Belgium. She was there for a month, playing three evenings each week, all sold out. People came from Germany, France, England and the Netherlands to see her. As her music doesn't fit in any category (except maybe super avant garde), her audiance didn't eather. Classical music lovers, people from the Jazz-scene, punks, gothics, rich and poor, all kinds of people gathered there.
And I swear to you, within half an hour 80% of them was crying because her litanies of pain and isolation are so powerful...
Play this very loud, and don't listen to it in the dark and on your own unless you are quite confident of yourself...