Sugarland: Jennifer Nettles & Kristian Bush/ Associated Press photo

It all felt very casual: No opening act, no frills (unless you count stage fog), casual outfits and fan requests helping to determine the set list for Sugarland's concert Wednesday at sold-out Mystic Lake Casino amphitheater.

Jennifer Nettles and Kristian Bush, who usually seem like an odd couple in concert, seemed to have more fun together than ever. There was a palpable playfulness between them. Nettles, who was wearing a day-glo top and sandals, is a lot less physical than she used to be; her first baby is due in November.

But she remains one of country's best in-the-moment performers, someone who wings it with panache whether riffing on fans' handmade signs or coaxing a shy 4-year-old girl to sing with her onstage. She truly seems to enjoy what she's doing and that's infectious. Not to mention that she has one of the most potent -- and twangy—voices in country music.

It's too bad that Sugarland's 95-minute set included so many not-so-great songs like "Incredible Machine" and "Find the Beat Again" (which sounded like a 1980s MTV rocker).

The In Your Hands Tour – it's all about the requests – meant that the set included "These Are the Days," "Genevieve," "Little Miss," "We Run" and "Life in a Northern Town." The request section was smartly followed by the guaranteed showstopper, "Stay," a stripped down tug-at-your-heart ballad with a slight gospelly organ undercurrent.

That number ranked as the night's highlight along with "Baby Girl," during which Avery Evans, 4, and her mom, Jennifer, joined in. (The girl, who has been battling a brain tumor at St. Jude's, was chosen by K102 to sing with Sugarland.) Avery was shy and Nettles handled the girl's reticence with patience and grace. By song's end, Avery was dancing a bit and waving her arms in unison with the crowd.

Afterward, Nettles asked Avery, "Was that fun?" The girl nodded and then blew a kiss with her hand to the crowd.

Sugarland's set list from Wednesday:
Wide Open/ Stuck Like Glue/ Settlin' / Everyday America/ It Happens/ Tonight/ These Are the Days/ Genevieve/ Life in a Northern Town/ Little Miss/ We Run/ Incredible Machine/ Stay/ Love/ Baby Girl/ All I Want To Do/ You Make My Dreams Come True (Hall & Oates) > All I Want To Do reprise/ Find the Beat Again ENCORE Something More/ Sugarland