Pro-Satan shrieking is to heavy metal as left-handed relief pitching is to baseball: There’s just never enough to go around. Which is why Ronnie James Dio is still finding work. Heavy metal? The guy’s got the shelf life of plutonium. Next month, RJD will kick off his fifth decade as a gigging rocker, and in that time he’s fronted some of the genre’s most cartoonishly dark combos. The prideful Dio left Rainbow in 1978 after Ritchie Blackmore begged him to move away from his trademark wizards ‘n’ witches themes and start penning love songs. As luck would have it, Black Sabbath at that time just happened to be in the market for a well-coifed antichrist to replace Ozzy Osbourne for its portentously insignificant Heaven and Hell project, and Dio was with the band when it actually recorded a tune called “Stonehenge.” His on-again, off-again relationship with Sabbath has kept Dio in the metal vanguard, and provided him with an ever-changing army of directionless white boys who always have their “hook ’em horns” salutes at the ready. Of course, that same salute can be had by pretty much anybody who can wax evil in an upper register. Wail with Dio and openers Division, Trust No One, and Mere Mortals tonight at midnight at Jaxx, 6355 Rolling Rd., Springfield. $20. (703) 569-5940. (Dave McKenna)