I'm guessing it's this from the BBC4 opress release - no dates yet:

The Story Of The American Folk Revival

A three-part series that tells one of the key stories of 20th century America.

The opening film features the Carter Family, Jimmie Rodgers, Robert Johnson, Blind Lemon Jefferson, Mississippi John Hurt and other blues and hillbilly singers who were discovered by record companies and folklorists in the Twenties and Thirties.

The second film enters the "dream life of the American left" with "hobo" Woody Guthrie and "jailbird" Leadbelly.

In the final film, the earlier singers are rediscovered and celebrated by a new generation of Americans, who tell their own stories about how they used the idea of a purer, simpler past to create something quite new – the exciting sounds of Sixties folk.

Featuring a stunning soundtrack, the series also includes rare archive and contributions from Joan Baez, Judy Collins, The Band, The Byrds, Odetta, Harry Belafonte, The Kingston Trio and The Weavers, as well as survivors and their families from the first wave of recorded folk.

To accompany the films there will be a screening of a concert from London's Barbican celebrating music from the series.