Whenever a new musical genre is celebrated by the press, the volume of generic releases by cash-in artists multiplies tenfold. Jungle is the current buzzword tripping from the pundits’ tongues, and even the dorkiest dance acts are sticking sped-up breakbeats behind their normally pallid sounds (What up, Everything But the Girl?). But Spring Heel Jack’s Jon Coxon and Ashley Wales (responsible for some of EBTG’s beats on its last CD) are two of jungle’s genuine auteurs. Jack’s new album, 68 Million Shades…, and a companion disc of remixes, Versions, showcase the frenetic, pre-millennial tension inherent in drum ‘n’ bass’s messed-up beats, as well as a love of late-’60s/early-’70s swingers (from Lee Perry to Ennio Morricone to Miles Davis) and a healthy respect for modern classical (where would Jack be without John Cage’s chance theories or György Ligeti’s luminous webs of sound?). The rangy twosome makes a pre-release tour (68 Million Shades… will be out domestically in February) opening for one of techno’s most dependably innovative acts, Orbital. At 7:30 p.m. at the 9:30 Club, 815 V St. NW. $15. (202) 393-0930. (CP)