I love the Avett Brothers, but in case you didn't already know. I'm a huge fan of John Prine too. He wrote that song. He comes up a lot on the Avett Brothers Pandora channel too.
Started off a few days ago with Jamie Johnson on Pandora. It gets a good dose of Coe, Haggard, Cash, and Jr in there too.
Then kicked over to Chris Stapleton. A few more recent artists get tossed in there, not as heavy on the outlaw contingent.
And just switched over today to Tedeschi-Trucks Band. Getting my southern blues on.