With their first two albums the Books--Paul de Jong and Nick Zammuto--devised a breathtaking new kind of chamber pop. They relied heavily on digitally chopped-up guitar, cello, banjo, and violin, and once in a while they'd add some vocals (theirs or other people's), but most arresting was the way they uncovered music in sampled chunks of found dialogue. Set amid ingenious, roomy arrangements, the inflections and rhythms of ordinary speech became melodic. Though the Books' new Lost and Safe (on Tomlab, like the others) has been described as comparatively song oriented, the pieces aren't any more conventionally structured than their previous sound art; it's just that Zammuto's voice has become a steady presence. His singing is in itself unremarkable, none too different from the standard indie-pop murmur, but original lyrics now play a greater role in the group's audio collages, juxtaposed with samples in ambiguous interplay. "An Animated Description of Mr. Maps" is a composite portrait of its title character rendered in sung lines ("He often wondered what a million people would look like scattered randomly across a moonless sky") that flow cryptically into spoken-word passages ("He frequently wears a full beard and sometimes glasses"). Based in western Massachusetts, the Books gave their first live performance in October 2003 at the Third Coast International Audio Festival here in Chicago; this week's dates are part of their first tour. EKG opens tonight's show; see also Monday. Sat 5/7, 10 PM, Reynolds Club, University of Chicago, 5706 S. University, 773-702-8289. Free. All ages.