One of the most enduring images out of this summer’s Newport Folk Festival came courtesy of Spirit Family Reunion. They were a motley crew on a sunny afternoon — six of them, dressed in clothes that could have been Dust Bowl vintage and playing an array of instruments, from acoustic guitar and upright bass to fiddle, banjo, and the washboard.

Their harmonies were as close and high-lonesome as anything you’ll hear on old Alan Lomax field recordings, but their energy was thoroughly modern, folk musicians with rock-star swagger. And they’re all in their 20s and live in New York City.