PIG MOUNTAIN Enjoy your metal served up thick with a side of sludge? Guitarist/vocalist Dustin "Doob" Outen, bassist Ricky Culp and drummer Dillon McKinnish infuse plenty of dark emotions amidst the gruff vocals and heavy instrumentals of Charlotte's Pig Mountain. During an Off the Record performance last year, the band said they were more concerned about slogging their wares through the musical atmosphere than offering any kind of message in the lyrics. Mission accomplished. Steel-toed boots recommended for wading through this trio's trough. With Witch Mountain, Lord Dying, Monarchist. 9 p.m. $7. The Haunted Mill, Belmont.