Brent Hinds, the co-founder of Grammy-winning heavy metal group Mastodon who played with the band for 25 years before his departure earlier this year, died on Wednesday. Brian Jost Reents, Deputy Chief Medical Examiner Investigator of the Fulton County Medical Examiner’s Office, confirmed Hinds’ death to Rolling Stone. “We are in a state of unfathomable sadness and grief,” the band wrote on social media Thursday. Editor’s picksIn a 2009 interview with Rolling Stone, Hinds explained how he learned to play guitar. “There are moments of leftfield eccentricity: the swamp-beast psych of ‘Creature Lives,’ or ‘Spectrelight,’ an over-the-top blitzkrieg with guest roaring from Neurosis’ Scott Kelly,” wrote Rolling Stone.