“They’re the British bluegrass guys!” “They’re folk-rock on steroids!” “The little banjo band that could.” Those are some of the ways that Radio.com‘s panel of music experts described six-time GRAMMY-nominated band Mumford & Sons, whose album Babel was one of the big success stories of 2012. Watch our Inside The Album Of The Year video below to see the story behind one of rock’s most unlikely arena headliners.

We spoke with experts, including Leah Greenblatt of Entertainment Weekly, Anthony DeCurtis of Rolling Stone, James Montgomery of MTV News, Radio.com‘s Jillian Mapes, author Alan Light (The Holy or the Broken: Leonard Cohen, Jeff Buckley, and the Unlikely Ascent of “Hallelujah”), Stryker from KROQ and Booker and McCabe from AMP Radio  and weigh in on the British band’s road to the GRAMMYs.

Next week, look for our Inside The Album Of The Year installment on fun.

Tune in to the GRAMMYs on CBS February 10 at 8PM EST/PST.

– Brian Ives, Radio.com