Since American Roots music is difficult to define, it might be easier if you listen to some of the year’s best …like the Grammy-nominated “Hold On” by Alabama Shakes.

“Rolling Stone” Magazine named that Alabama Shakes tune their top song of the year, beating other Top 10 tracks by Taylor Swift, Bob Dylan, Kanye West, Frank Ocean and Jack White. Not bad for a band that 18 months ago had a hard time selling out 500-seat clubs. This year, they’ve opened for the Drive-By Truckers, Jack White and Robert Plant, and sold out shows in the U.S., Europe, the U.K., Australia and South America.

Alabama Shakes also earned three Grammy nominations: Best Rock Performance for “Hold On,” Best New Artist and their debut album, “Boys & Girls” is up for Best Recording Package.  They didn’t even release their first full-length album until April of this year.

Another debut band with a banner year was The Lumineers. The Denver-based trio has two Grammy nominations: Best New Artist and Best Americana Album.  Its self-titled debut came out in the spring and has stayed on the charts since then, going Gold and selling close to 520,000 copies to date. The official video for “Ho Hey” is a hit, too with more than 20 million views on YouTube so far.

No discussion of 2012 Roots music could be complete without a mention of 24-year-old John Fullbright. Unlike the two bands mentioned already, John’s critically-acclaimed and Grammy-nominated debut “From The Ground Up” was a totally independent release. This means he put it out himself, without the help of a record label, large or small, raising the money to record the album via the fan funding web site Kickstarter. The resulting record has landed atop many critics’ Top 10 lists, with the song “Gawd Above” singled out for special praise.

It wasn’t just the first timers who were releasing brilliant Folk, Americana and Bluegrass albums this year. There were new albums from Darrell Scott, Gretchen Peters, Willie Nelson, Lyle Lovett, and Bonnie Raitt, just to name five. On the bluegrass side,  Special Consensus gave us some fine new music, as did The Boxcars and the Steep Canyon Rangers.

Mumford and Sons came back in a big way, earning six Grammy nominations for their second album, “Babel.” It sold 600,000 copies in its first week, proving the British band was no one-hit wonder. The boys also proved they weren’t too big to still have fun, showing up to lend their voices and picking prowess to a track on dobro wizard Jerry Douglas’ new album, “Traveler.” Jerry told me that when Paul Simon found out they’d gone into the studio to record this version of his song “The Boxer,” Paul wanted in on the fun. So he added a couple of guitar parts, some bells and vocals to the mix.  All in all, it was a great year for American Roots music.