“Doom metal” now describes bands as diverse as drone-rumblers Sunn O))) and hard-rockers Danava, but what did it mean originally? Tonight’s show is a journey to the center of this bleak music that more or less started with Black Sabbath (but trust me, you don’t want to hear Ozzy anymore). Sweden’s Candlemass formed in 1985 and have gone through many lineup and stylistic changes, but the dedication in the liner notes of their 1986 debut, Epicus Doomicus Metallicus, still applies: “To hatred, bitterness, pain, depression, and hangovers.” Their new offering, King of the Grey Islands, with Solitude Aeturnus singer Robert Lowe, is a slow march into dead-air AOR. “Of Stars and Smoke” is this year’s best 1987 single, evoking early Savatage strut over suffocating Sabbath/Trouble chording. Openers Daylight Dies, who honor both Swedish death/doom and American Southern rock (sparingly), are a real sight to be seen. MIKE MEYER