The sumptuous, magisterial gloom of Circle evokes the unrelenting climate and geographical remoteness of the sextet's native Finland. In the early 90s their noisy, riff-driven rock was distinguished mostly by Spacemen 3-like drones and unusual time signatures, but over the years they've meticulously cultivated a sound of their own, reconciling the metronomic intensity of Krautrock, the ethereal drift of ambient music, and the baroque flourishes of prog-rock. The group's fifth album, Pori (released last month in the U.S. by Feldspar, making it the first Circle album available domestically), is a concept album about their coastal hometown, but no translations are provided, so I'm not sure what the concept is. Terse, distorted guitar riffs alternate with billowy, airbrushed arpeggios, gurgling electronics mingle with seallike saxophone bleats, and faux-Gregorian chants glide over stuttering, hypnotic grooves. The pieces develop more like techno tracks than rock songs, the various elements--a drum pattern here, a snippet of melody there--subtly changing shape. The brand-new Andexelt (Tumult) is even better: the MO is the same, but the occasional excesses of Pori--including most of the vocals--are stripped away. Tight drum and bass patterns stretch elegantly to accommodate shifts in the foreground, like the spacey flute extrapolations on "Odultept" or the puzzle-piece interplay of guitars and piano on "Zomilate." But as trippy as Circle can come across, they're always deadly precise. Sunday, 9 PM, Empty Bottle, 1035 N. Western; 773-276-3600.