Black Cobra is a San Francisco sludge metal combo (formerly out of L.A.) that will smother you with blunt, brutally crushing riffs and shout in agonized glee as you gasp for breath. The above video for "Sugar Water" provides ample evidence of their violent sonics. Joining them tonight at The Summit, 2210 Summit St., will be Providence heavies Howl and this city's own Struck By Lightning, who are along for this entire U.S jaunt. Doors open at 8 p.m., with music at 9. No word on cover charge.