Saxophonist Dave Rempis is best known so far as a member of the Vandermark 5, where he replaced Mars Williams back in 1998. His initial contributions on alto brought a hint of west-coast cool to the group's molten performances, but before long he added tenor to his arsenal and cranked up the heat. The quintet's breakneck tunes, improvisational vehicles though they may be, are as tightly mapped out as Chicago's streets, and Rempis fits himself neatly into Vandermark's grid system. But in his other main group, Triage, the topography looks more like downstate Illinois. The trio--which includes drummer Tim Daisy, who recently replaced Tim Mulvenna in the V5, and bassist Jason Ajemian--moves through its compositions with a measured, inquisitive grace. On Triage's recent debut, Premium Plastics (Solitaire), the players take advantage of the space, alternately dropping out in a round-robin array of solos and duets, and the tunes, especially the 19-minute "Spasm," are calmly episodic. That's not to say there aren't moments of intensity: on "Pegging In" they hit their boiling point, Rempis's alto fluttering in its upper register and Ajemian locking into a repetitive pattern that approaches the monolithic stomp of William Parker. Daisy, for his part, seems to be in constant motion, spreading rhythms around the kit like peanut butter. Not all the tunes stick, but at least one, Ajemian's tender "Fellini's Blues," definitely does. These guys are some of the jazz scene's younger participants, and as such they still reveal a certain obeisance toward the usual free-jazz heavies--but they're adding new wrinkles with each performance. Solitaire label head Phil Mosberg also performs with his quartet, which has just released its second album, The New Balance. Wednesday, January 9, 8 PM, HotHouse, 31 E. Balbo; 312-362-9707.