In all its alt-country glory, Wilco reaches for the sky

Wilco is on the road in support of "Sky Blue Sky," a collection of warm folk-rock and alt-country gems reminiscent of the group's early, earthy sound. But everything Jeff Tweedy and company have explored in the last decade -- psychedelic soul, lush pop, ambient drones -- was woven into the mix, and with few exceptions the songs (old and new) felt freshly considered. "I Am Trying to Break Your Heart" was transformed into an ethereal march -- all twinkling keyboards and walloping drums -- that narrowed into a ribbon of pure noise.

There is nothing this band can't play, and in the course of nearly two hours there was hardly anything it didn't: winsome pop ("Jesus, etc." and "Hummingbird" ), hard rock ("Spiders (Kidsmoke)") , dreamy meditations ("On and On and On" ) , and Woody Guthrie ("California Stars" ). Wilco may be the world's only experimental country band, and in avant-garde guitarist Nels Cline , the newest member in a notoriously shifting lineup, it feels like Wilco has found a key piece of its musical puzzle.

Cline didn't so much play solos as embark on mind-bending excursions made of searing, serpentine runs or punishing pedal steel. When he swooped into the blues waltz "Side With the Seeds," loosing shards of razor-edged notes, or punctured the sedate surface of "Handshake Drugs" by rubbing at his strings like they were a stubborn spot, Cline wasn't just being interesting -- he was supplying the songs' dark, complicated subplot.

"What you once were isn't what you want to be anymore," Tweedy sang on " Shot in the Arm." Happily, he and his ever-changing, endlessly inventive band don't hesitate to do something about it.

Joan Anderman can be reached at anderman@globe.com. For more on music visit boston.com/ae/ music/blog.