Main’s Robert Hampson has come a long way since he led the Spacemen 3-derivative Loop back in the late 80s. (Hampson is Main’s only current member, but most of the project’s recordings also feature his former band mate Scott Dawson.) It’s not that he’s abandoned trancey minimalism, but rather that he’s spent the last seven years refining and streamlining it into increasingly spare guitar abstractions. While bits of standard rock firepower surface on Main’s earliest work (two 12-inches captured on the Hydra-Calm CD in 1992), most of its subsequent recordings are purely amorphous soundscapes. The electric guitar has always been Hampson’s basic sound generator, but a battery of effects and unusual playing techniques has utterly disguised the instrument, and reportedly he no longer bothers with one onstage. While many of Main’s numerous recordings drift through woozily hypnotic patterns, on more recent work, such as the new live recording Deliquescence (Beggars Banquet), Hampson disrupts the soothing calm with shards of sound, mostly without apparent rhyme or reason. Clicking and humming machines or dropped objects are mimicked; the focus is as much on these “accidental” sounds as deliberately “musical” ones. This performance promises plenty of low-key, minimalist beauty, and it should be mildly fascinating to observe Hampson’s process, but either sitting down or being hopped up on something couldn’t hurt. The duo Bowery Electric (see Spot Check), which gets remixed by Main on its new Vertigo, headlines. Tuesday, 10 PM, Double Door, 1572 N. Milwaukee; 773-489-3160. PETER MARGASAK

Art accompanying story in printed newspaper (not available in this archive): photo by Tom Sheehan.