David Thomas has carried on a highly ambivalent engagement with rock 'n' roll for nearly three decades. As a member of Rocket From the Tombs and Pere Ubu he helped write punk history with songs like "Sonic Reducer" and "Non-Alignment Pact," but during the Ubu hiatus of the mid-80s his solo work swapped guitars for accordions and bassoons, and when the band made its ill-starred lunge at the brass ring in the early 90s Thomas's contemptuous onstage manner made it seem like he viewed rock concerts as empty rituals. So I didn't expect much from the RFTT reunion last year--and certainly not the ferocity and conviction with which the balding, hobbling Thomas delivered the power-chord-driven teen angst of "Final Solution" and "Life Stinks." That readiness to rock out has rubbed off on guitarist Keith Moline and trumpeter Andy Diagram, aka Two Pale Boys, the electronically augmented duo that's backed Thomas on five albums since 1996; their new 18 Monkeys on a Dead Man's Chest (Smog Veil) opens with withering feedback blasts, then lurches into some splendid, Seeds-worthy riffs. But they haven't forgone their gift for spectacular dynamic shifts: "Nebraska Alcohol Abuse" transitions from huge, clanking rhythm loops to hushed, hallucinatory horn washes, matching Thomas's swings from bleating horror to whispered rue. Another constant in this collaboration is mournful nostalgia; Thomas's protagonists dwell in neon-lit memory, lamenting the loss of places and people they loved. Stag Party and Uncut open. Saturday 23, 10 PM, Empty Bottle, 1035 N. Western, 773-276-3600 or 800-594-8499, $10.