I made this track for International Strange Music Day; http://fiftyninety.fawmers.org/content/international-strange-music-day
It's not really a Black Mass - it's a reading of the original version of "The Battle Of Maldon", a poem in Old English about the defeat of a Viking raiding party by a group of East Saxons on August 11th, 991.
But I think it works pretty well as the soundtrack to some kind of eldritch demon-summoning ceremony.
Please keep your comments respectful, honest, and constructive. Please focus on the song and not the demo.