Not all sweetness for Sugarland

Perhaps there was some strange energy left over from the Dixie Chicks, who’d just finished the set of inaugural Nokia Theatre shows with the Eagles on Saturday?

No, Sunday headliner Sugarland deserves full credit for its own efforts to change some stereotypes about what it means to be a hit country-music act.

Midway through its crisp set topping a bill at the shiny downtown venue, the personable Georgia duo of Jennifer Nettles and Kristian Bush waded into some topical territory. As they started their song “Happy Ending,” words started to appear on the two large balloons and two round screens that adorned the stage: “Hope is alive . . . Love is true . . . Peace is possible . . . Faith is real.”

And then four names: Mahatma Gandhi, Nelson Mandela, Martin Luther King Jr. and, incongruously, Neil Armstrong.

If that didn’t make the point, the pair and their five-member band segued into a solid version of “Where the Streets Have No Name” by U2 -- the unquestionable model for faith-as-action in music of their generation. That was followed by Sugarland’s own pointed “One Blue Sky,” accompanied by video images of the post-Katrina devastation of New Orleans and the Gulf Coast.

Sure, it’s not quite on par with the Chicks’ adventure into political commentary. But it gave substance and meaning to a set of otherwise highly appealing and spiritedly delivered country-rock songs detailing life in, to use one of their song titles, “Everyday America” -- though that song too bears some bite in its central line, “A little town and a great big lie.” It also neatly wove the tour’s title (“Change”) and tie-in (the Shalom Foundation, which aids Guatemalan families in extreme poverty) with the music and performance.

It didn’t matter that the next song was the relatively frivolous “Down in Mississippi (Up to No Good).” Hey, even U2 has some songs that are just fun, right? Heck, most of the material from Sugarland’s two albums, 2004’s “Twice the Speed of Life” (when the group was a trio) and last year’s “Enjoy the Ride,” is plenty entertaining, rounded out Sunday by “Who Says You Can’t Go Home” (the star-making duet from Nettles and Jon Bon Jovi) and two other amusing covers: Beyonce’s “Irreplaceable” (countrified without irony) and Def Leppard’s “Pour Some Sugar on Me” (slight irony perhaps).

But simply knowing there’s more to it gave it all a sense of, well, more.

Which might have helped the two other acts’ portions of the evening. Little Big Town not only referenced mid-’70s Fleetwood Mac with its sparkling two-women/two-men harmonies (several songs in part evoking that older band’s song “The Chain”), but left no doubt about it with a note-for-note version of the Mac’s “Go Your Own Way.” Opener Jake Owen has the basic goods of a contemporary country star -- such six-pack anthems as the self-explanatory “Yee Haw” and the looks of a scruffier Tom Cruise -- but he needs a bit more spark before he’ll start to rival Toby Keith.