Mixing live improvisation with pre-programmed beats, Sound Tribe Sector 9 crafts circular compositions flavored with funk, hip-hop and psychedelia. Stir in a dedicated jam band fanbase and you might expect a concoction appealing only to retro ravers and neo-hippies who yearn for the days when Pink Floyd played Pompeii. STS9 avoids that jam band sinkhole by eschewing wanky solos and concentrating on interlocking grooves spun from break beats, electronica and dub. True, their forays into funk fusion can lapse into a smooth jazz coma, but more often STS9 achieves the swinging heights of prime Stevie Wonder. Like dance club wunderkind Pretty Lights, STS9 tours with an immersive light show, complete with an LED Mayan pyramid backdrop. Yet, unlike concert hall DJs, STS9 has a keener sense of composition and a knack for danceable, otherworldly grooves. Older material tends toward the soothing end of late-period Tangerine Dream, but STS9's continuing trend toward livetronica yields down-tempo, pulsating rhythms that recall the brittle brilliance of Chromatics. The jam band cliché is that you need drugs to enjoy the genre, but STS9's cyclical mash-up of trance, prog and jazz is the drug. With Umphrey's McGee. $34-$40.50. Aug. 28, 7 p.m. Uptown Amphitheatre, 1000 N.C. Music Factory Blvd. 704-916-8970.