Question:  Hydra is an album by Within Temptation and contains guest appearances by an American metalcore vocalist best known for being the vocalist of what two bands?
Sentence (from "Howard Jones (American musician)"): Howard Jones (born July 20, 1970) is an American metalcore vocalist, best known as vocalist of the bands Killswitch Engage and Blood Has Been Shed, and as the current vocalist of Light the Torch, formerly known as Devil You Know.
Relevant evidence: Yes