When Austrians Peter Rehberg, aka Pita, and Christian Fennesz first came to Chicago, two years ago, the idea of a couple guys hunching over their laptop computers onstage was still fairly ridiculous. As if to acknowledge that their “performance” was visually unengaging, the two set up with collaborator Jim O’Rourke in a far back corner of the Empty Bottle, which forced the emphasis onto the barrage of abstract electronic sounds they were unleashing through the PA. These days laptop artists still aren’t exactly threatening to put guitarists out of business, but they’ve certainly become a more common sight in rock clubs. In fact, affordable software has made it all too easy for any jamoke with a G3 to call himself a musician, and I’ve since suffered through many an aimless, noodly ‘puter set: Pita and Fennesz still have few peers when it comes to maximizing the instrument. On his most recent album, Get Out (Mego), recorded onto his hard drive in hotel rooms in New York, Tokyo, Amsterdam, Paris, and Oxford as well as at home in Vienna, Pita unveils a shifting sound world studded with surprises. Fragile, elegiac melodies are crowded by increasing waves of distortion and high-end frequencies; bleeps, clicks, hums, and glitches hop between stereo channels like lottery balls; elusive electronic tones fold in on themselves and then explode. On Fennesz’s latest, Plus Forty Seven Degrees 56′ 37″ Minus Sixteen Degrees 51’ 08″ (Touch), he furiously shuffles, juxtaposes, and collides glitchy electronics, harsh noise blasts, soothing tones, and the occasional pretty melodic snippet into a layered stream with rigorous attention to detail; the resulting rhythms are fascinatingly inventive. Granted, the best way to absorb any of this stuff is through headphones, but there’s something to be said for experiencing it at club volume too. Wednesday, 10 PM, Empty Bottle, 1035 N. Western; 773-276-3600. PETER MARGASAK

Art accompanying story in printed newspaper (not available in this archive): Pita photo by Otmar Brauer, Fennesz uncredited photo.