On which group is this artist, who signed and numbered the lithograph for the pre-ordered album "By the People, for the People," currently a vocalist?
By the People, for the People:  If the album was pre-ordered through the Sony Music Store, it was packaged with a free lithograph of the lyrics to "Dull Boy", signed and numbered by Mudvayne vocalist Chad Gray. Chad Gray: Chad Gray (born October 16, 1971), is the lead vocalist for the groove metal supergroup Hellyeah and former lead vocalist for American heavy metal band Mudvayne.
i don't know