As deep as Chicago’s free-improv scene runs, there aren’t too many folks devoted exclusively to what’s usually called “lowercase sound” or “electroacoustic improvisation,” which is characterized by small sonic gestures, collective development, and an unconventional aural palette that gravitates toward tonal extremes. Last year Jon Abbey, who runs the important New York label Erstwhile—perhaps the most visible and tireless proponent of this stuff—sent me a self-released, self-titled CD-R by a couple of Chicagoans, Graham Stephenson (trumpet) and Dave Barnes (electronics). I didn’t get around to listening to it until very recently, but now that I have it’s clear that these two are pushing in a very different direction than most local improvisers.