Rob, I'm glad you liked this
I did the "grandma" phrase in a stronger head voice but I tried a much lighter shade for the rest (closer to King's interpretation).
I made the music bed, my recording through and through safe for the drums & solos of course.
As for the harmonies, I just copied what is on the record, always using a very light, piercing tone.
The truth here is that although it sounds like he's got 5 different harmonies, he's got only 1 harmony, doubled a few times.
I did the same thing. One main voice and 1 harmony done 3 times if I remember correctly.
I'm pretty sure I've posted a cover of Mercyful Fate's Come to the Sabbath, you might enjoy that.
Definitely an acquired taste and I'm glad it stayed that way