True to form, guitarist Bill Frisell kept everyone -- including his trio mates -- guessing at the Barns at Wolf Trap on Sunday night.

Working without a set list and speaking just long enough to introduce bassist Viktor Krauss and drummer Kenny Wollensen, Frisell played whatever sprang to mind, mixing his own quirky compositions with songs written by a curious assortment of tunesmiths, including Stephen Foster, Bob Dylan and Burt Bacharach.

The intimate yet freewheeling atmosphere was in keeping with the small-combo recordings Frisell has made during the past decade. At times the guitarist seemed to be conversing with himself, tinkering with a digital delay box that created sonic loops and triggered both subtle and dramatic mood shifts. Frisell's fascination with gadgetry is inherently lighthearted, though, and there were plenty of moments when he used electronics to colorfully underscore his affection for simple melodies ("Hard Times"), ringing harmonies ("Just Like a Woman") and the occasional pop ballad ("What the World Needs Now Is Love").

When a honky-tonk refrain or a splintered funk beat suddenly surfaced, Frisell reveled in Telecaster-driven twang, lowered tunings and jarring "stomp box" effects that amused even his longtime tour mates. Echoes of Jim Hall and Jimi Hendrix, two of Frisell's primary guitar influences, were heard too. Having collaborated with Frisell for a decade or more, Krauss and Wollensen were prepared for anything that came their way, be it a loping shuffle, noirishly orchestrated mood piece or bright, shimmering guitar anthem.

-- Mike Joyce