The band is on tour into September, performing most at fairs and festivals.

Their grass-roots ascent is more typical of rock groups than country singers.

“Most new country artists that come out don’t really have a fan base,” said Luke Lewis, co-chairman of Universal Music Group Nashville. “These people had original songs, which is even more impressive to have an audience and a fan base that reacts to original music. It wasn’t just a bar band doing covers.”

Lewis first saw Sugarland perform in a Nashville club filled with fans who had driven five hours from Atlanta. He offered them a contract that night.

“It made a statement that they had that many fans already,” Lewis said. “I saw them a few weeks later in Atlanta … and it was packed, too, and most of the people knew the songs.”

After their debut album was released last fall, Atlanta also provided a strong breakout market until the rest of the country could catch on – something Lewis was certain would happen. The group’s latest single, “Something More,” is at No. 3 on the charts.

“These aren’t just pretty faces or voices. It’s a complete package,” he said. “I didn’t feel like we were being particularly astute by signing them.”

The trio, who took their name from Sugar Land, Texas, because they liked the way it sounded, co-wrote all 11 tracks on the record, a blend of country, folk, pop and rock that’s already produced two hits (including “Baby Girl”).

With bright harmonies and catchy melodies, the songs tell of new love, leaving home, dreams fulfilled and kicking back.

“If we came out in the ’70s, we’d be alongside the Eagles and the California scene. If we came out in the ’90s we’d be triple A (adult album alternative). It just so happens that this year the kind of music we do sounds country,” guitarist and background singer Kristen Hall says.

Hall, Jennifer Nettles and Kristian Bush each were veterans of Atlanta’s music scene when they formed Sugarland about two years ago. Hall, 42, was a singer/songwriter who had recorded a few solo albums; Nettles, 30, fronted popular local bands Soul Miner’s Daughter and the Jennifer Nettles Band; and Bush, 34, was half of the major-label folk-rock duo Billy Pilgrim.

On stage, lead singer Nettles is the focal point. She has a twangy voice that can be husky one moment, wispy the next.

“Whatever ‘it’ is, she’s got it,” said Johnny Gray, music director of country station WKHX-FM in Atlanta. “She’s an unbelievable performer.”

With three singer/songwriters and lush harmonies, Sugarland recalls ’70s supergroups such Fleetwood Mac, the Eagles and Crosby, Stills and Nash – groups famous for their feuding as well as their music.

Bush doesn’t worry about a meltdown.

“I can see where that happens because sometimes one member becomes more popular than another,” he says. “In this band we kind of each take on a job at a different point. There’s so much less ego involved when you’re sharing the blame or the accolades.”