Gregorian Chant dudes doing an Ozzy cover tune:
http://www.youtube.com/watch?v=lVqAPofFgT4
Same dudes covering Metallica:
http://www.youtube.com/watch?v=H7csvgL-G3E
I can’t do youtube here right now.
Is it ‘The Benzedrine Monks Of Santo Domonica’?
Home listening bookmark.