Dual Natures

Jeff Tweedy conducted the first moments of Wilco’s concert Monday at the John Anson Ford Amphitheatre with the sober deliberation of a warrior girding for battle, all clenched concentration and eyes-tight-shut intensity.

On the opening “Sunken Treasure,” he finger-picked a single-chord drone on his acoustic guitar, slowly pulling the other three musicians into a hammering, percussive climax. When he came to the title phrase of the third song, “I Am Trying to Break Your Heart,” all the instruments except the drums dropped away, leaving Tweedy repeating the line like an incantation as he marched in place.

At this point, you wondered what kind of state he was working toward--private ritual or rock ‘n’ roll release?

But all of a sudden Tweedy blinked his eyes as if coming out of a trance. As the band strummed the opening chords of the next song, “War on War,” he began strolling around the stage and making eye contact with fans. Before long he was a full-blown stand-up comedian, bantering easily and at length with the audience.

Tweedy’s transformation could serve as a literal representation of his Chicago-based band’s dual nature--down-to-earth pragmatism and eyes-on-the-stars dreaminess.

Wilco began as a so-called alt-country band, but soon there were a lot more Beach Boys, Rolling Stones and Replacements in the mix, and although being difficult to pin down has probably contributed to the group’s commercial limitations, it’s also attracted and solidified one of pop’s most substantial cult followings.

After a well-publicized art-versus-commerce split with Reprise Records last year and the recent release of a documentary film that charted that episode, the band’s profile--and its perceived status as champion of artistic integrity--has never been higher.

Despite that added edge, Monday’s concert (the first of two sold-out nights at the Ford) was refreshingly unburdened by any self-congratulatory posturing along those lines.

The musicians went about their business with a direct, blue-collar approach and rapport to spare, intensifying the rock tunes and applying light touches to the more spacious arrangements.

Tweedy, bassist John Stirratt and keyboardist-guitarist Leroy Bach would often step aside to flank drummer Glenn Kotche, making him the center of attention as he contributed distinctive touches with his chimes and cymbals or pounded a rocker into submission.

Additional musician Mike Jorgensen came and went throughout the show, generating sounds from his laptop, and Scott McCaughey and Ken Stringfellow from the second-billed Minus 5 periodically chipped in on percussion and keyboards, stirring up a communal spirit.

The songs from the new Wilco album, “Yankee Hotel Foxtrot” (released by Nonesuch Records), with their pairing of achingly beautiful melody and atmospheric abstraction, were prominent, but it was 1996’s unruly two-CD set “Being There” that dominated, with selections ranging from the meditative “Sunken Treasure” to the rocker “Misunderstood,” a platform for a Sonic Youth-level instrumental freakout.

Wilco also included two of its songs from “Mermaid Avenue,” its 1998 collaboration with Billy Bragg on some unpublished Woody Guthrie lyrics.

These stylistic leaps somehow seemed inevitable, unified by one of pop music’s most evocative and emotional sensibilities. If Tweedy was indeed trying the break his listeners’ hearts--and judging from his music that’s one of his highest aims--he should consider Monday’s show an unqualified success.