Brittany Howard, the powerhouse 24-year-old frontwoman for Alabama Shakes, isn't much for red carpets. But duty called for her double-barreled Grammy debut, so she fancied up her hair and had fellow Southerner Billy Reid design her some dresses. At the MusiCares tribute to Bruce Springsteen, the pre-awards black-tie gala, the Shakes delivered a devastating "Adam Raised a Cain," with Howard lowering her gritty, supple punk-blues voice to an astonishing Springsteen-like roar. Then, for the Grammy tribute to Levon Helm, Howard sang "The Weight" alongside Elton John, Mumford & Sons, Zac Brown, T Bone Burnett and her hero Mavis Staples, taking the "Crazy Chester" verse and nearly outshining everyone else. Howard brought her grandmother along, and backstage they made the most of it. "I met Adele," Howard said from her home in Athens, Alabama. "My nana knocked on her dressing-room door and made her come out! She's fearless."
The Shakes didn't take home a statue, despite three nominations, but they had a blast. And they ended the whirlwind week with their first appearance on Saturday Night Live, which in some ways was the best of all. "So many of our heroes have played on that show: Tom Petty, My Morning Jacket," Howard says. "The Grammys are stressful. On SNL, I just got up there and had fun."
It was another big moment in the whiplash rise of the Shakes, who in two years have gone from rural oddballs playing Black Sabbath and James Brown covers to an A-list Southern soul-rock franchise. The band's 2012 debut, Boys & Girls, a set of impassioned originals with a Stax/Volt kick, has sold 430,000 copies, topping iTunes and Amazon's sales chart in February – nearly a year after its release – thanks to a post-Grammy/SNL bump. The single "Hold On" (Rolling Stone's Number One song of 2012) is at five million YouTube hits and counting, and Howard has become a sort of soul-queen anti-diva, not afraid to sweat, howl, rock Rubenesque curves, shred on her turquoise Gibson SG or bust geeky dance moves.
The Shakes grew up in and around Athens, Alabama, a small city between Birmingham and Nashville. Until recently, drummer Steve Johnson, 27, held down a job at the Browns Ferry nuclear plant, and played hard rock with an outfit big on Tool and Rage Against the Machine. Bassist Zac Cockrell, 25, weaned on Booker T. and the MGs, worked at an animal clinic, and guitarist Heath Fogg, 28, covered T. Rex and Bowie with local rockers Tuco's Pistol when he wasn't painting houses. Like his bandmates, Fogg was reverent of his region's musical history. "We're so close to Muscle Shoals," he says of the studio where Aretha Franklin and the Stones, among others, recorded. "They should be teaching kids about that in school – it's such an important part of our history. But nobody knows anything about it."
Howard was delivering mail for the U.S. Postal Service when the Shakes began to take off. Raised by an Elvis-loving mom and a Motown-loving dad, she was a mixed-race kid who became a teenage punk rocker – an odd identity in Athens, where the Klan hosted a rally as recently as 2007 (though they were quickly driven back to their hole). The Shakes coalesced around Howard and Cockrell, who were high school pals, and were soon playing a mix of crowd-pleasing covers at local bars (they still do a killer version of Zeppelin's "How Many More Times"). A demo of a Shakes original found its way to Justin Gage, who posted it on his blog Aquarium Drunkard. The next morning, Howard's email account was flush with overtures from record labels and management companies.
The Shakes' North Alabama neighbor Patterson Hood of the Drive-By Truckers saw them playing at his local record store. "It was phenomenal," he says. "I said, 'God, this band could be played anywhere in the country! Everyone needs to see them!'"
The road forward was obvious. "When Brittany told me she was going to quit the post office, I was like, 'What?!' says K.J. Howard, her dad. "But she said, 'I'm going for it, Daddy. And I'm not gonna fail.'" Sure enough, by the end of 2011, the Shakes had a deal with Dave Matthews' ATO label, home to the Truckers and My Morning Jacket, and things accelerated rapidly. "I've been doing this for 27 years, and I've never witnessed anything like it," says Hood. "I'm super proud they're from home, 'cause I know what the odds are of being able to do something like that from where I'm from."
It's easy to read much of Boys & Girls – from the death-haunted opener, "Hold On" ("Bless my soul/ Didn't think I'd make it to 22 years old"), to the closer, "On Your Way" ("On your way to heaven, did you say I'll see you again?") – as Howard dealing with some very personal pain: specifically, the loss of her older sister and early musical inspiration, Jaime, who died of retinal cancer at age 13 in 1998. She doesn't like to talk about it, but she believes her sister's spirit has been looking out for her. "I needed a lot of strength to go to work in the morning, play a show when I'd get off, get two hours of sleep, go to work again, and spend all my money on studio time, just hoping, praying that maybe I can quit my job one day and do something that would make me happy," she says. "You gotta believe in something to do all that."
Back home in Athens, finally, Howard is thinking of the next album. Some songs are written (one, "Always Alright," turned up in Silver Linings Playbook and on SNL). Nothing is nailed down, but the Shakes aren't planning any big changes. "I like to keep things simple," Howard says. "I mean, we never expected the Grammys, we never expected to do world tours. All we did was go into the studio, because we wanted to be like a real band and have an album, and then it turned into all this."
This story is from the March 14th, 2013 issue of Rolling Stone.