Conversation so far:
Was Dark Roots of Earth an album title?
it was announced that the tenth Testament studio album would be called Dark Roots of Earth.
How many copies did it sell?
CANNOTANSWER.
What was one of the most famous hits on it?
CANNOTANSWER.

Question: Was there anyone else they made music with for this album?
Self-contained rewrite: Was there anyone else that Testament made music with for Dark Roots of Earth besides themselves?