Of rock guitars, goofiness and resolve

Wilco came to the Wiltern LG on Thursday in a new configuration that included a two-man rock-guitar army, but the group scored its biggest victories with some quieter moments near the end of the two-hour concert, and sealed the deal with some out-of-the-blue political comments.

The Chicago band opened its encore segment with a spellbinding version of its haunted, impressionistic “Ashes of American Flags,” and seven songs later ended the evening with British singer-songwriter Bill Fay’s “Be Not So Fearful,” a stately anthem of encouragement and reassurance.

Leader Jeff Tweedy added weight to both selections with his introductory comments, dedicating “Ashes” to “the people who were brave enough to burn flags when they didn’t like what was going on in our country” and prefacing “Fearful” with a stirring plea to reject the imposition of red-versus-blue divisions and work toward unity and communication.

Those moments represented a radical contrast with the bulk of the evening, which had paired Tweedy’s lighthearted goofiness as a host with the five musicians’ intense attack.

One minute the singer would be joshing easily with the crowd (there was a running joke about the presence of an 8-year-old girl in the audience, making Tweedy wary of his language and such lyrical subject matter as drugs), and the next he and the band would be revving up like a jet on a runway.

This kind of contrast has helped endear Wilco to one of rock’s most substantial cult followings, making it an exemplar of how to thrive below the music industry’s radar.

The band is worlds removed from the top of the charts and mainstream consciousness, as well as from trendiness and tabloids. Still, it commands an audience that on this trip sold out two nights at the 2,000-plus-capacity Wiltern.

A lot of it has to do with Wilco’s cause celebre art-versus-commerce skirmish with its then-record-label, Reprise, which two years ago advised against releasing the album “Yankee Hotel Foxtrot.” Wilco made the music available on the Internet, then signed with Nonesuch Records, which released the CD to much acclaim.

That’s a tough act to follow, but this year’s follow-up, “A Ghost Is Born,” maintains Wilco’s level of artistry while taking off in new directions, notably Tweedy’s indulgence of his rock-guitar urges.

Tweedy himself did most of the heavy riffing on the record, but for the band’s tour he’s brought in Nels Cline, the highly respected Los Angeles guitarist known mainly for his free-jazz and experimental work.

Cline, positioned in a thicket of pedals and other appliances, brought plenty of adventure to Thursday’s show, sometimes erupting in clouds of turbulence, sometimes locking in with Tweedy on cathartic climaxes that took the music into the realm of pure noise.

The guitarist also eased up when necessary, offering fiery if more conventional solos and an array of flavorful fills and flavorings, and fitting seamlessly into the tapestry formed primarily by two keyboardists and one of rock’s most musically inventive rhythm sections.

All of his work was marked by a clean elegance, even when it danced at the edge of chaos, and his presence elevated what had always been a decent-enough live band into an often-memorable one.

Cline also pitched in on a couple of songs by second-billed Carla Bozulich, another Los Angeles cult favorite for her varied solo work and her terms with the bands Ethyl Meatplow and the Geraldine Fibbers. The dusky-voiced singer and her three-member band played a set of new songs that ranged from a bouncy, Stones-like shuffle to jittery rock-noir to harsh blues-rock reminiscent of PJ Harvey.