If you've wearied of DJs who mash up one slick soulless pop song with another, head over to the Upstairs Lounge (see Best Dance Club in the Bars & Clubs section) on the second Saturday of the month for a prescription-strength dose of DJ Jim K's dubstep. Jim K's not a self-promoter, but he's an underground ambassador who's as knowledgeable as any of our best local DJs, with years of experience playing for Midwestern crowds. He started out spinning hardcore fifteen years ago during the early rave days in St. Louis, then flirted with drum 'n bass before establishing himself as a dubstep DJ, so he's technically right when he jokes that his current musical preferences might indicate he's "slowing down with age." But the beats he spins for the Internet radio show on dubstep.fm, or for the Dub Hz monthly at Upstairs, are dark, bass-laden reminders of London's early garage scene that retain all the genre's fresh, instrumental experimentalism.