see outtakes from the hyper-stylish pop duo!

Amy Heidemann can't count the number of ways her life has changed since April 12, 2011. That's the date she and Nick Noonan, her bandmate in the ultra-bubbly pop duo Karmin, uploaded to YouTube a cover of Chris Brown's “Look at Me Now” that's since been viewed more than 55 million times. But as Heidemann sits in the dressing room of a Los Angeles photo studio, the singer admits that these days she might be most excited about having professionals around to do her hair. “We joke that we pinch ourselves every day,” she says, her vintage-inspired pompadour halfway to completion. “But we had to stop because we were bruising.”

Karmin's dream began at Berklee College of Music, where Heidemann and Noonan—who are now engaged—met as students in 2004. She was singing; he was studying jazz trombone. “After we graduated we decided we should start a group,” says Noonan. “At the time it was gonna be a modern version of Simon & Garfunkel, but it kind of evolved from there.” That's one way of putting it: As Karmin's YouTube clips demonstrate—they've also posted popular covers of Lil Wayne's “6 Foot 7 Foot” and “Super Bass” by Nicki Minaj—Heidemann is a surprisingly adept rapper; there's no way to be unimpressed by her handling of Busta Rhymes' insanely speedy verse in “Look at Me Now.” Both members cite Kanye West as a huge influence on the development of their approach. “He really pushed us to ask, ‘Why can't we do hip-hop?'” Noonan says.

Whatever happens next, Karmin are enjoying their success now—and, true to form, they're sharing the experience with their fans. Amid the covers on their YouTube channel is an endearingly dorky clip of the band getting ready to go onstage with the Roots at Tufts University. “Such a moment for us,” says Heidemann. “That, and the one where we hear our song on the radio for the first time. Do you remember the movie That Thing You Do!? It was just like that.”

Read the entire story, and see more Karmin photos, on nylonmag.com.