Starting a band in a town like St. Joseph, Mo., is hard enough without being black and underage. The city isn't exactly a music mecca, nor is it the kind of place inclined to embrace three African-American siblings playing high-octane rock 'n' roll. So, when 18-year-old bassist Isaiah Radke and his brothers, singer-guitarist Dee, 20, and drummer Solomon, 16, decided to pick up instruments and bash out classic three-chord punk as Radkey, they were beginning at a distinct disadvantage.

"People will give me shit for saying bad things about the city, but they didn't give us a chance at all," Isaiah says. "For instance, we wanted to play this place called Hammerjacks. They saw our picture and said they don't book rap groups."

Hometown support isn't something Radkey has to worry much about these days. In recent months, the band has received love from plenty of other places, including The New York Times, Spin and NME. It's not hard to pinpoint what has sent the group barreling into the hearts of critics a generation or three older than its members: Its scrappy, melodic punk has become a conduit for nostalgia. With indie rock and EDM now the dominant sounds of millennial youth culture, Radkey recalls a time, not long ago, when being a teenager meant diving into the pit and screaming along to whoa-oh-oh choruses. Who needs St. Joseph when you've tapped into the shared adolescence of the entire country?

Of course, the difference between Radkey and, say, your high-school punk band, is that Radkey is really, really good. Weaned on their father's Misfits records—Dee's demon bellow is a dead ringer for Danzig's—the brothers got together in their shared bedroom three years ago and began writing speedy songs inspired by anime, comic books and the occasional real-world concern (see the raging semantics lesson "'N.I.G.G.A.' Is Not OK"). Their chemistry is remarkable, though not surprising: Aside from sharing the same DNA, all three Radkes were homeschooled, making them "abnormally close," Isaiah says.

"While we ended up weird, as most kids do, I think it's working in our favor," he says. "Weird is interesting."

With few opportunities in St. Joseph, the band crammed into the family minivan and headed for more welcoming scenes in Kansas City, Mo., and Lawrence, Kan. An appearance at the Afropunk Festival in New York led the group to record a pair of EPs, 2012's Cat & Mouse and the recent Devil Fruit. In October, the trio flew to England, making its television debut on Later...With Jools Holland. Things are going so well, the brothers' father, Matt, quit his job at Wal-Mart to manage the band full-time, making the siblings the primary breadwinners in their household. It's an awkward position for three musicians still learning what it means to be a band. Like most kids their age, though, the Radkes aren't too worried about the future. Maybe with good reason.

"We've found a system that seems to work: Listen to good music, write songs you love, and accept nothing less," Isaiah says. "Hopefully, us loving it will mean others do, and hopefully that'll work for a good career."

SEE IT: Radkey plays Wonder Ballroom, 128 N Russell St., with Black Joe Lewis & the Honeybears, on Sunday, Dec. 1. 7:30 pm. $18 advance, $20 day of show. All ages.