Battlefields, who hail from an unpublicized part of Minnesota, and Lyon, France’s Overmars are a transatlantic match made in sludge-metal heaven. Both play at patience-testing paces (Overmars’ forthcoming Born Again is one 40-minute song), favor bowel-tickling, nearly sub-sonic tones, and sing about esoteric subjects in ways that are difficult to hear anyway. Venue owners at the Charleston could fear that the band’s guttural tones would cause it to crumble, but since they both play so slowly, they should probably just check for signs of erosion when the concert is done.

Thu., Sept. 3, 8 p.m., 2009