What kind of music is this?

Watch "Colby Reunion 2011 - Band" on YouTube

So three weeks ago, my little sister, Erisa and I were watching the Colby reunion events, and got captivated by the band they had. I learned that a banjo is special because it has strings laid over a drum! Genius. Anyway, got a good video of the magic which is (insert appropriate genre title) music.