Like most of the UK's volatile dance scene--a quickly evolving culture of techno, hip-hop, ambient, breakbeat, and acid house--jungle music is almost strictly a club thing; you dance to it, but you don't buy the records. Artists hide behind names like Omni Trio, Spring Heel Jack, DJ Krust, Rogue Unit, and Dillinja, but Goldie is beginning to become a well-known face. His increasing popularity, his remixes for folks like Scarface and Bjork (who headlines this show), and, more important, a debut album that manages real cohesion--Timeless (ffrr/Metalheads)--suggest he'll remain vital beyond tomorrow morning. Goldie's jungle conveys a strong R & B-rooted pop appeal, with dense beat projections married to sophisticated vocals and thick layers of synth washes. Seen as an outgrowth of techno and breakbeat--its jacked-up, furious rhythms often cram upward of 200 beats into a minute--jungle actually conflates a great number of divergent styles, from the dance subgenres mentioned above to dancehall and acid jazz. Jungle isn't so much a style as an approach with infinite possibilities, in which a dizzying array of complex beat patterns become the music's center, while melodies and textures do the undergirding. It's hyped as the next big thing, but it's doubtful that jungle will raid U.S. charts anytime soon: it's mostly instrumental and it makes the relentless throb of techno seem like a beginners' lesson. (Goldie spins Friday at the Smart Bar, 3730 N. Clark; call 549-4140.) Saturday, 7:30 PM, Riviera Theatre, 4746 N. Racine; 275-6800 or 559-1212.