Earlier this week, TIME caught up with the Afro-Norwegian duo as they headed to the NBC studios to rehearse with the Roots before their performance on The Tonight Show Starring Jimmy Fallon.
In their down time, the pair both constantly have earphones on, often singing out loud or dancing to a silent rhythm.
"I'm listening to some sketches we did in Norway, songs," says Vincent "Vinz" Dery during a short car ride, chuckling. "Listening to ourselves."
But even given the high stakes, neither appeared nervous. "We're kind of confident because the chemistry between us is great onstage,"says Nico Sereba, the other half of the duo. "I mean, we're playing with the Roots, which is one of the best bands in the world."
In the video above, Nico & Vinz sit down backstage before the show to discuss their unique sound and how they balanced work — as high school substitute teachers — and music.
But be warned: their catchy, upbeat song will get stuck in your head for the rest of the day.