Grace Potter of the group Grace Potter and the Nocturnals performs after the Christie's Green Auction for the ‘Bid to Save the Earth’ benefit Wednesday, April 11, 2012, in New York. (John Minchillo/AP)

She’s opening for Nashville nice guys Kenny Chesney and Tim McGraw on tour this summer, but Grace Potter hasn’t been minding her manners. She howls. She thrashes. She stomps across the stage with a fury that will make you wonder if the stage said something nasty about her mother.

“I don’t know if it’s coming across properly,” the 29-year-old admits. “People might think I’m coked up because I’ve been everywhere on that stage. I run, like, 21 / miles every night.”

After clocking thousands of miles on the road with her band, the Nocturnals, the effusive rock singer has earned a reputation for her fiery live show. But this is Potter’s first stadium tour — and the stadiums are filled with thousands of finicky country music fans, no less. The stakes are high, and the stage is sprawling. There’s even a catwalk, allowing Potter to stomp a little closer to 50,000-ish ticket-holders as they search for their seats, wondering who let this blond hurricane into the building.

“I think there’s a real ferocious approach to what we do as a band, and I don’t like the idea of phoning it in, even though it’s a stadium of people who are there to hear country music, not rock-and-roll,” she says. “It’s really fun for me. ”

It’s also the latest break for a singer who has been heralded as an overnight success every night for the past seven years.

Grace Potter performs during the MTV, VH1, CMT & LOGO O Music awards. (Skip Bolen/GETTY IMAGES)

Potter first made ripples outside of her native Vermont in 2005 by adopting the business tactics of countless jam bands: incessant touring and lots of fan interaction. But that second part got trickier after she signed with Hollywood Records, a label owned by Disney. Her popularity swelled as she continued to plug away on the jam-band circuit, but she managed to retain the scrappy image of an artist who was on the verge of something bigger.

The fourth Grace Potter and the Nocturnals studio album, “The Lion the Beast the Beat,” arrived in June. And after recording a duet called “You and Tequila” with Chesney in 2010, Potter’s on the road with him through the end of the month. (The tour touches down at FedEx Field on Sunday night.)

Potter says there’s a purpose to her party-crashing. “Think about what makes a band burn out,” she says over the phone from a recent tour stop in Portland, Ore. “They get too successful too fast. And then they take it for granted. And they get entitled. And they get picky. We don’t ever allow ourselves that possibility.”

Which means she’s constantly sniffing out new turf in hopes of converting new hearts. And it’s working. Her brand of rootsy rock-and-roll is familiar enough to gain entry with an array of audiences, and her stage presence is rowdy in a way that’s tough to forget.

“She’s actually brilliant,” said global business magnate Richard Branson backstage at the Virgin Mobile FreeFest at Merriweather Post Pavilion last September. “It’s very nice to have Grace as a friend.”

And everyone seems to want to have Grace as a friend. While Branson was swooning, Potter was strutting across a Merriweather stage, windmilling away at her Gibson Flying V. Less than a year later, she has her own signature model of the guitar. She also has her own brand of Lake Champlain chocolate bar. Cabot Cheese paid for her first tour bus. And she’s hosting a music festival in Burlington, Vt., next month that’s sponsored by Green Mountain Coffee.

Sure, corporate sponsorships have become commonplace in pop music, but Potter talks about these brands like they’re her pals, fellow Vermonters (save for Gibson) who are trying to run businesses that do good. Her alliances have reinforced a warm-fuzzy sense of community pride while helping her band thrive in an industry where record sales continue to slump toward oblivion.

Grace Potter performs during the Coachella Valley Music & Arts Festival. (Frazer Harrison/Getty Images for Coachella)

She still calls Vermont home. She recently renovated an old structure on the artist compound where her parents raised her, a plot of land in rural Vermont they’ve jokingly dubbed “Potterville.”

It was a great place to grow up, despite being a bit of a musical no-place. Potter says Vermont’s lack of musical output made her ravenously curious about other pages in the American songbook, blues and gospel especially.

As a kid, when she had the chance to see live music, she soaked up every detail, sometimes through teary eyes. She remembers being 9 years old at a James Brown concert in Boston with her family, bawling because she wanted to be onstage so badly.

Twenty years later, she’s onstage most nights of the year but has no plans to change her permanent address. “For all the flack that we get for becoming successful, you get people who really respect how firmly planted our feet have been in Vermont,” Potter says.

She’s talking about the despair that she heard from her hardest die-hards once she signed with Hollywood. On top of having to share their favorite singer with the rest of the world, fans also noticed that Potter’s hair was a few shades lighter. Her boot-cut jeans shrunk to Daisy Dukes. Her sneakers turned into stilettos.

She was changing her image, but Potter says some fans read it the wrong way.

“The misconception about the record company is that they were the ones who got me wearing short skirts, or got me to do my hair blond, or got me to dance around onstage and start doing different things with my clothes,” she says. “No, that was actually all me.”

She embraces a look that matches her ambition but still finds herself battling the T-shirt-and-corduroys image she forged during her earliest days on the tour circuit. “I hear it all the time,” she says. “ ‘What happened to the Grace Potter who didn’t used to wear makeup?’ ”

Superficial as that gripe might be, it’s the reality of slowly, steadily growing toward fame. Gaining new fans can mean losing old ones.

“But they’re not really lost,” Potter insists. “They’re just waiting for you to come back to that thing that they like that you do.”

Beneath the mascara and the sparkly dresses, she thinks she’s been doing it all along. She only gets 35 minutes onstage opening for Chesney and McGraw, but she taps into the sweaty spirit of the tiny club dates of yesteryear, stomping around the space between her dues-paying past and her potentially starry future.

“I love living in the gray area,” Potter says. “I think it’s a really inspiring place to be.”

Grace Potter and the Nocturnals perform at FedEx Field on Sunday.