CLUTCH have become an institution of rock, and not just in their home state of Maryland, where you shall be shunned if you consider yourself deep into music and don’t know their name. CLUTCH have long been one of the leaders of the sludge rock revival; along with headbangers, their fan base consists of brainiacs, poets, comic hounds and literati due to their imaginative, often highbrow lyrics. Their last outing, “Earth Rocker”, was an album that solidified the band’s international presence. Holy Christ, what fun CLUTCH’s eleventh slab, “Psychic Warfare” is. Here the band goes raw and tears it up.