In Sugarland, love has many forms

COHASSET - There is no backstage at the wonderfully homespun South Shore Music Circus, so Jennifer Nettles and Kristian Bush, the duo that performs as Sugarland, had to stride down the aisle and climb up onto the stage like eager entrants at a community talent show. A bright, bustling set of anthemic country-rock followed, and so did the deliciously odd feeling that these arena-ready stars had astral-projected to our humble suburban venue.

What a treat. Like the Dixie Chicks (and not many others) before them, Sugarland fuses twangy traditions and shiny pop hooks without sounding as if the act was built from a kit. The pair's warmth and generosity hasn't been subsumed by the radio-readiness of their material. Nettles's powerhouse technique hasn't erased the human emotion in her voice. For an hour-and-a-half Sugarland found the elusive sweet spot between intimate ambience and grand gesture.

Fleshed out to a seven-piece live ensemble, the group is touring in support of its third album, "Love on the Inside," and kicked off the concert with the collection's quintessential track. "Love" is a dramatic meditation, made almost entirely of questions, and it names the thing this collection plumbs in all of its mysterious, moon-like phases. Mainstream country-pop isn't the most varied or nuanced genre, but Sugarland did a fine job lassoing the reckless rush of new love on bluegrass-flavored "We Run," the sting of loss on "Joey" and "Genevieve," and the pleasure of living in the moment on "All I Want to Do."

That last song is Sugarland's current single, and it's slimmer and sillier than the others, but it felt heartwarming coming on the heels of a guitar giveaway. (If she managed to wrestle the instrument away from her elated dad, a little red-headed girl is signing up for lessons today.) The rest of the set was filled with feel-good or empowering rockers ("Baby Girl," "Settlin'," and "Who Says You Can't Go Home," Nettles's Grammy-winning duet with Bon Jovi) and those with a more complicated message, like "Everyday America."

A gorgeous, truncated cover of R.E.M's "Nightswimming" was a tease, but a sassy singalong on Def Leppard's "Pour Some Sugar On Me" made a pitch-perfect show closer. Nettles and Bush, who played rhythm guitar and rowdy mandolin, were in each other's faces all night, gleeful and flirtatious, and their energy is electric. It's not hard to see why rumors swirl around the recently divorced singer and her married musical partner.

The tale of hard-won liberation on "Stay" is achingly familiar in pop music, and the switcheroo on the song's last verse is the oldest trick in the book. But Nettles understands better than most singers how short the distance is between tender and tough. In her hands romantic desperation felt new, and emancipation was cause for one more collective cheer.

Local singer-songwriter Les Sampou opened with a set of sturdy folk and blues.

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