Have you seen the Japanese Buddhist monk who goes by the name Kossan1108? He posts videos of himself overdubbing his own vocals and traditional instruments to classic rock songs.
Here’s one of him doing Metallica’s “Enter Sandman”. He starts singing at 1:08. There’s a random weird voice for about 13 seconds starting at 3:20. The song ends at 5:02, and then he meditates through the rest of the clip