(AP) - He's done baseball, Vietnam, and the Gettysburg Address. Now it's country music that is getting the Ken Burns treatment.

The PBS documentary maker's newest project will see him dig into the roots of country music - tracing its history to where it is today.

Among those who will be profiled will be the Carter Family, Hank Williams, Johnny Cash, Willie Nelson and others. Don't go rushing to check your local PBS listings for it just yet. It isn't due out until 2018.