Jeff Tweedy led Wilco through two hours of tunes at Merriweather Post Pavilion on Sunday. (All photos by Kyle Gustafson/FTWP)

Sunday night at Merriweather Post Pavilion, the Chicago-based sextet, lead by singer-songwriter Jeff Tweedy, played a two-hour set, heavy on tunes from its latest record, “The Whole Love.”

In its original incarnation, Wilco was unafraid to rock out state-fair-style, playing a traditionalist take on roots rock, replete with power chords and wonky solos. But by the turn of the century, the group had outgrown Americana. On ’02s “Yankee Hotel Foxtrot,” Wilco went weird, reinventing itself as a bleeping and blooping take on folk-rock that owed as much to AOL modem noise as it did Woody Guthrie.

“The Whole Love,” the band’s eighth record, follows in that spirit. Its opening song, “The Art of Almost,” which kicked off Sunday’s set, is built around pummeling rhythms and spaced-out squiggles, courtesy of lead guitarist Nels Cline. No acoustic guitars necessary. Getting weird has, somehow, only strengthened Wilco’s appeal.

At least, for some fans. Each new Wilco record is accompanied by a bit of grousing by those who miss the old days, whenever they may have been. When “A Ghost is Born” came out, fans yearned for the dizzy textures of “Yankee Hotel Foxtrot.” When that record came out, old-time loyalists dubbed the Beach Boys-style pop of “Summerteeth” the band’s golden era. When the Wilco’s debut album, “A.M.,” arrived in ’95, people pined for Tweedy’s defunct alt-country band, Uncle Tupelo.

Live, Wilco still lets its freak-flag fly, though. The band regularly pushed strummy alt-rock tunes, like “Born Alone” and “Shot in the Arm” into noisy atonal crescendos. Cline, a veteran underground jazz musician, hammered the bridge of his guitar with a metal bar, pounding life into mid-tempo rock tunes. But some of the old-time intimacy has disappeared. Part of Tweedy’s success as a songwriter came from his willingness to take risks, both in the music and the lyrics. His songs were fraught with uncomfortable disclosures and moral ambiguity. Nowadays, he’s in better spirits and his songwriting has shifted in a more clever, Randy Newman-esque direction.