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 deliberate wanderer. Performed solely on two classical guitars with some alligator clips, tin foil and wood sticks affixed to the instruments for textural percussion, this concept is as honest and time-tested as it gets. Kolosko's opening, two-part piece, ''Yangisse Jarabi,'' is inspired by vocal music of the Aka Pygmies and the luscious sound of the Malian kora, an escapist's dream of an instrument. The sparse, elegant bounce of the second movement in a strange way reminds of Vince Guaraldi's ''Peanuts''-based jazz piano themes. It's light on the brain and perfect to work along to, and you can't help but perceive the joy these two guys are having along the way. Cosley's original piece, ''Ensō,'' is similarly evocative and unpredictable, with slow, sporadic pulses and spider-web scales. Somehow, amidst the high-minded artistic pursuits, both contributors make the stories in the song easy to follow. The exercise itself is meditative, so it's hard to resist the heart of the album: five improvisations that achieve ghostly peaks by cruising in and out of Middle Eastern plucking, European classical motifs and crunchy American jazz moves. Because the guitars themselves have such a honeyed tone, Kolosko and Cosley are free to use all the tricks they'd like, going any which way musically. Most notably, as a conversation between two artists both trying to paint the perfect circle, the project is a success because of the multi-colored dynamic of two patient players. - MIKE OLCOTT (Portland Press Herald, February 25, 2010)