It’s their version of Helen, a chestnut previously recorded by J.D. Crowe and East Virginia.
ClayBank is Tyler Thompson on banjo, Jacob Greer on guitar, Gary Trivette on bass, and Zach Arnold on mandolin. They guys are currently working at Castle Ford Studios in Boone trying to finish up a debut album. Look for that sometime in 2016.
You can find more videos on their Facebook page.