Acapella.

Angels gathered around the demon...
Calling its name with batting wings.
All of their expressions had failed to discover,
Poor judgement in the way it sings.
Erased in their celestial grace...
Lying still was its sorrowed demise...
Loving depression had failed to uncover,
A song of Death in the way it cries.
♠ ♠ ♠
This is about Death Metal vocals, or the guttural vocals that people label as "growling" or "screaming."