Classical guitarists take their listeners far with the exotic 'Ensō':

Portland is a rocker's town. Sure, there are viable artists of all varieties around, but the Port City's got a hard-blues, Elvis Presley obsession. Stroll through the Old Port on a weekend night, and gnarled power chords rule the soundscape.

For as deeply gratifying as 3-minute, 30-second pop-song structures can be, folks forget this is only one use of music through the ages, and these Kelly Clarkson catharses are a dime a dozen nowadays. Enter well-traveled classical guitarists Nathan Kolosko and Dan Cosley, whose searching Zen marvel ''Ensō'' offers a listening experience all its own.

First, the rough premise. Ensō is an ancient Zen Buddhist painting practice that involves brushing the perfect circle. How your circle is brushed fully reveals your character as an artist. As music unfolds over time, a musician practices his circles as long as his improvisation carries him.

''Ensō,'' the album, recorded in Japan, is a subtle but delibera